There have been a lot of claims in this field some of which may be dubious. However, the following paper is interesting and is available in PDF format at:
http://198.63.56.18/pdf/puthoff.pdf
It can be viewed in html via Google.
Essentially it claims that experimental research has already shown some effects indicating that "vacuum fluctuations can be altered by technological means."
It also claims that with regards to energy in vacuum fluctuation there are indications that such may be occurring with the powering up of cosmic rays, energy release from supernovae and gamma ray bursts.
It talks in vague terms about possible potential for spaceflight.
The symposium summary paper was set up for a seminar at Sussex University and run by the Institute for Advanced Studies at Austin. This is a
"The Institute for Advanced Studies at Austin is a private research institute in Austin, Texas, established in 1985 to explore advanced concepts in forefront scientific areas. As the theoretical and publication division of EarthTech International, Inc., its activities range from theoretical studies of such fundamental issues as gravitation, inertia and cosmology, to laboratory studies of innovative approaches to energy generation.
The Institute has established a track record of excellence both with regard to publication in leading scientific journals, and in the development of new technical concepts and technologies, including the successful pursuit of patents. Its expertise is sought after by both corporate and government entities, and its personnel regularly serve various corporations, foundations, government agencies, the Executive Branch and Congress as consultants on leading-edge technologies and future technology trends. (An example is participation by the Intitute personnel in NASA's Breakthrough Propulsion Physics Program.)
The Institute's Director, H. E. Puthoff, Ph.D., is a member and officer of several professional organizations (NY Academy of Sciences, American Association for the Advancement of Science, American Physical Society, Society for Scientific Exploration); is listed in American Men and Women of Science, Who' Who in Science and Engineering, Who's Who in the South and Southwest, Who's Who in the World; and has been distinguished as a Fetzer Fellow (1991)."
