Quantum theory predicts, and experiments verify, that so-called empty space (the vacuum) contains an enormous residual background energy known as zero-point energy or ZPE. This energy derives its name from the fact that at temperatures of absolute zero (- 273o Celsius), elementary particles continue to exhibit energetic behavior. Advances in the theories of zero-point energy, nonlinear thermodynamics, and Connective Physics open up the possibility of cohering this energy for practical purposes -- in effect tapping the zero-point, and thereby accessing a universe-sized source of energy.
Originally, the possible uses of zero-point energy was thought to be of significance only for such esoteric concerns as small perturbations in atomic emission processes. But now, zero-point energy theories suggest new ways to understand inertia and gravity (and thus potentially control these forces!). Such theories may also be able to explain anomalies such as Sonoluminescence, the inhibition of spontaneous emission, and the generation of short-range attractive forces (e.g. the Casimir Effect). More practical applications include “mining” these vacuum fluctuations for practical uses such as spaceflight and such far-out possibilities as “warp-drive” space propulsion systems.
Theoretical contributions have been done by such pioneers as Nobel laureates Ilya Prigogine, P. A. M. Dirac, John Wheeler, and Julian Schwinger. Prigogine, for example, has shown that the second law of thermodynamics can be expanded to include systems in which order evolves from randomness -- a result also obtained by Puthoff who utilized theories of zero-point energy to obtain an equivalent result.
The critical factor here is that linear systems tend toward increasing entropy (i.e. the result of two inputs being the sum of their corresponding outputs), whereas under certain conditions, nonlinear systems have been shown to evolve toward macroscopic order. Such nonlinear systems imply transient or apparently uncontrolled systems, but the reality remains that clever designs can and do provide means to skirt traditional understandings of thermodynamic limitations and literally tap into the surrounding universe for unlimited amounts of useful energy.
Experimentally, the emphasis has been to demonstrate an energy device whose power output exceeds the power input as measured through conventional methods. The quest of such a device has been pursued -- with some success -- by dedicated and innovative researchers, including Tesla, Moray, DePalma, Newman, Boyer, Puthoff, Fleischmann, Pons, Bearden, Graneau, Patterson, Ward, and many others.
It is sometimes assumed that the era of overunity energy research began with the pivotal work of Pons and Fleischman in their discovery of what came to be referred to as cold fusion. While the possibly premature nomenclature of “fusion” might not be strictly applicable, Patterson has taken this work even further, achieving significant results in both energy production and the transmutation of elements. In many respects, while this work cannot be overestimated in its profound importance to a better understanding of physics and chemistry, it nevertheless has shown greater potential for the transmutation of elements than it has for energy production.
T. E. Bearden, on the other hand, has described in detail the operational principles of overunity electromagnetic engines under development by Johnson, Takahashi, and Kawai. Bearden is also heavily involved in the MEG Scalar Energy Device, which is reputed to have attained an energy output of 5 to 20 times the input. Unfortunately, economic pressures have supposedly delayed the introduction of this potential breakthrough device. Anomalies from hydrosonic pumps and Superconductivity at room temperatures have, meanwhile, continued to fuel the research for ever improved energy generating devices.
Many of the technologies which are already considered “proven” are included in the World of Free Energy, by Peter Lindemann. Joe Firmage has created an organization named Motion Sciences, which has brought scientists and researchers from a variety of other organizations and groups in an attempt to jump-start the integration of these efforts into our everyday lives. And as a further indication of the progress of research, one can review any of several Selected New Energy Patents, or visit the Institute of New Energy.
Interestingly, while fledgling theories abound -- from regauging scenarios to zero-point energy theories to ether concepts -- all viable systems tend to congregate around a few fundamental principles. These include the need for nonlinear, transient (as opposed to steady state), far-from-equilibrium, and rapidly oscillating systems. These in turn make the possibilities of mechanical overunity systems extremely difficult to achieve, and the mathematics to describe the systems considerably more complicated. The good news, however, is that designs incorporating extensions of Connective Physics, inertial field theories and Mach’s Principle -- when combined with state of the art solid-state and other fields of physics -- provide the potential for practical, attainable new energy devices.
The immediate and down-to-Earth future of ZPE and related theories is very exciting. It is now clear that these fields of scientific endeavor lead simultaneously to:
1) Over-unity energy systems,
2) Inertial Propulsion systems which do not require reaction mass (i.e. throwing something in the opposite direction as in the case of using oars, propellers, or rockets), and by extension,
3) an understanding of the physical dynamics of Consciousness.
Zero-point and Connective Physics energy generating devices require no fuel of any kind to burn, transform, and otherwise modify -- and thus leave no waste products (i.e. no pollution) of any kind. Instead, by the “simple” expedient of tweaking the rest of the universe in a clever way, unlimited amounts of energy may be obtained from the fabric of space. Inertial Propulsion devices transcend so-called “anti-gravity” systems in that a gravity field (such as the earth) is not required in order to achieve significant propulsive thrust. In both cases, the universe is contributing, and thus connected to the propulsion and/or energy systems. The connection mechanism (involving both mass and charge) may then be extended to include the connectedness and physical dynamics of consciousness.
Connective Physics is based upon the simple premise that if one can enter a local system, accomplish work, and then exit the local system before it can respond in a conserving, equal-and-opposite reaction, then useful work can be accomplished without paying for it with local energy. Within the theory is the possibility of energy systems which provide useful energy in convenient forms (such as electricity) and which simultaneously do not burn anything, transform anything, or in any manner result in a waste product. This feature is incredibly important, in that some concepts of over-unity energy devices still convert some fuel to a lesser energetic state. The lesser-energetic state may ultimately then constitute the waste product or the pollution from such a device. The fact that the waste product may not now be considered pollution may be only temporary. The moment that there is a build up of the less-than-useful commodity, it will become “pollution”. The quest for over-unity energy machines must thus consider that ultimately, the most viable and future-oriented direction is the development of devices that use no fuel. Period. Energy generating devices based on The Fifth Element fulfill this stringent requirement, but then so do zero-point energy, vacuum polarization, and other such devices.
Zero-Point Energy allows for the possibility of tapping energy directly out of the fabric of space. According to Moray King : “there is evidence that the zero-point energy is not a passive system but actually is a manifestation of an energy flux passing through our space orthogonally from higher dimensions. Wheeler  derives such hyperspace channels (wormholes) in his geometrodynamics. Also, a picture of nonlocal connections is implied by quantum physics’ EPR Experiment , Bell’s Theorem , hidden variable concepts , the basis of Quantum Theory itself , and Hyperdimensional Physics.
“The zero-point energy can be modeled as an electric flux flowing orthogonally though our three-dimensional space. As this flux vibrates, it generates an electric field component in our space creating “mini-white holes” (flux entrances) and “mini-black holes (flux exits). The random action of this higher dimensional process gives rise to the observed zero-point fluctuations in three-dimensional space.” 
Zero-point energy is sometimes referred to as “vacuum polarization”. In this view, additional “higher” dimensions are not an essential characteristic (but are not precluded by it). Instead the nature of the vacuum itself is under investigation. In such vacuum considerations, Bearden [7, 8] has shown theoretically that asymmetrically regauging the scalar potentials “can freely increase the potential energy of the system, without performing work on it. Regauging opens the system so that excess energy is automatically furnished by the external vacuum potential.”
“Puthoff has pointed out a cosmological feedback principle in the zero point energy of vacuum which constitutes a continual exchange of energy between any charged particle and the rest of the charged particles in the universe.”  The Fifth Element theories of Ward  would suggest Puthoff’s cosmological feedback principle could be expanded to constitute a continual exchange of energy between any massive particle and the rest of the massive particles in the universe. In fact, it has been suggested that all massive particles have charge! So called “neutral particles” are merely combinations of equally charged positive and negative charges, such that the net sum of the charge is zero. Thus the connecting link between massive-charged particles is the basis of the cosmological energetic principle throughout the universe. [An alternate view is that Mass is an illusion, and merely a convenient representation of electrical charge.]
Inertial Propulsion systems (even Levitation) are inherent in Connective Physics. Again, the essence is to push a massive object and then back away prior to the object being able to react to the push and push back in accordance with Newton’s Third Law. In effect, the non-simultaneity of Newton’s Third Law once again allows one to enter the system, cause an effect, and then exit the system before paying the price.
Work on this aspect of Connective Physics is being accomplished by Dan Sewell Ward of Quantum Genesis, L.L.C., James Woodward of California State University at Fullerton and Ning Li of the University of Alabama. Woodward, for example, has been studying the connection between inertia and gravity, and suspects that “giving an object a sudden kick should cause minuscule, temporary fluctuations in its mass.” “He thinks it should be possible to ‘steal’ a little extra push from the distant parts of the universe, and do it repeatedly. This process might form the basis of a fantastic new kind of propulsion.” 
Clearly, Woodward is moving in the same direction as Ward. Li’s work on an anti-gravity device (using what is likely to be Superconductivity effects) could yield both rockets without propellants as well as power plants that run without fuel. Bearden  and King  have also mentioned superconductivity as a viable alternative to developing over-unity energy and advanced propulsions systems.
The Physical Dynamics of Consciousness may also be involved. This involves a fundamental paradigm shift from the 20th Century’s science of separateness, Zero-Sum Games, and “not enough”, to all things connected and no limits. It’s importance cannot be overemphasized. Just as recent experiments in quantum physics have shown connectedness between particles with information exchanged at speeds many times that of the speed of light, the realization and experimental confirmation of inertial field and Zero-Point Field theories will inevitably transform our view of the universe. This connection also ultimately suggests a physical dynamic of consciousness, albeit quite likely at the quantum level.
Bearden  has said that “Violation of local energy conservation by a powerful free energy device can produce a local curvature of spacetime (ST) in and around the operating device, unless preventive measures are taken. This ST curvature alters the local rate of flow of time, and thus affects all local operating things that exist in time. Note that the mind itself, and the thoughts and memories therein, also exist and function in time. These entities are therefore affected by the altered flow of time. Fairly powerful free energy devices -- say, of the power necessary for a medium factory -- thus can produce detrimental [or beneficial?] biological effects, not only upon the physical body but also directly in and upon the mind, memory, personality, and cognition. Unrestricted operation of the free energy device also gradually conditions and structures the local background potential upon the mass in the area, and upon the local vacuum potential.”
The philosophical implications of unlimited and connected energy and propulsive sources implied by both inertial field and zero-point energy theories both echo Bearden’s thoughts. It is inevitable that if all massive charged particles in the universe are connected, then it follows that this includes the biological aspects of consciousness. Many religious and philosophical traditions have advocated a connectedness of human consciousnesses (and potentially other consciousnesses, as well). It now appears that science is finally providing the details of the physical dynamics of such connectedness, and all part of the current research by diverse individuals and groups. What is being learned in the energy and propulsion fields will ultimately affect theories and research on the physical dynamics of consciousness.
(2/5/9) Implications are, of course, not limited to philosophical considerations. William James, in his Zero Point - Power of the gods website has taken what in hindsight might be viewed as a logical if not obvious extension and linked the physics of zero point energy with the power sources of the ancient gods, aka the Anunnaki. Admittedly, Mr. James presents the connnection as "an adventure series which focuses on the unlimited potentials of Zero Point Energy and the ancient gods of civilizations long past." The fact remains, however, that one can learn far more history from historical novels than from so-called non-fiction, the latter being merely a limited interpretation of the facts with said interpretation being constrained by being forced to adhere to mainstream, traditional interpretations. The wealth of Mr. James' efforts derives furthermore from connecting physics and history in such a manner so as to give greater credibility to both. A notable bonus is the fact that Mr. James' writings can also "stir the reader’s imagination to consider the possibilities of this fantastic energy source."