The pilot study cited indeed sounds interesting, since it's at odds with the most famous, and, to my knowledge, most thorough, UFO study, carried out by the Air Force in the "early days" of the phenomenon. The AF found (to its dismay) that the better the sighting, _the more likely the object in question was to be a genuine UFO_.
Of course, "UFO" means exactly that--_unidentified_ flying object. It appears to me that some of the posts re this suffer from the gross semantic leap that UFO=alien spacecraft.
Re holograms: I don't think most UFO sightings are literal holograms, but I think this is a good track to take, since they seem to deliberately "tease" witnessses with "impossible" aerial stunts. UFOs employ a sort of technological theater. Jacques Vallee and a few others see this as a possible catalyst for human evolution. I wouldn't be the least bit surprised to discover that we are someone else's artificial life experiment, and UFOs and similar phenomena are variables thrown into the mix to assist some vast psychosocial study.
It's also interesting that holograms were mentioned, as there is some evidence that the U.S. government has used holography to simulate security breaches on air bases--using UFO imagery! My best best is that these were psychological tests, but they could certainly be something else entirely...
As far as physical, uncontestable "proof" is concerned: we've got it, in one form or another. A number of truly strange implants have been removed from the bodies of self-claimed "abductees," with no satisfactory explanation for their composition. This doesn't mean aliens made them: it merely means they are an unknown, probably representing a technology of some sort. The literature on this is terribly scant, but there's some intelligent stuff out there if you dig. The website "CNI News" (www.cninews.com) is probably the best online source for nonsensational UFO claims (they also report on technology, physics and space exploration).
Dr. Allen Hynek co-authored a book on one of the most compelling mass sightings in history: "Night Siege: The Hudson Valley UFO Sightings." I think anyone who can walk away from evidence like this (and I've read dozens more) and still insist on an ultimately prosaic explanation is irrational. I contend that the UFO phenomenon, whatever it is (and it could be a lot of things, or a combination of many things) is a genuine unknown. And that's really all that's certain at this point. I broached the topic on a transhuman mailing list because I thought that it served as a working metaphor for many of the technologies we're concerned with, and maybe UFOs, far from being resolutely "alien," might actually be telling us something constructive about ourselves.
It's been noted that mathematical models of UFO sighting waves mirror B.F. Skinner's scedules of reinforcement. Do UFOs represent some form of cosmic Skinner Box, or a psychic thermostat? There's no arguing that our beliefs about the world (and, thusly our technologies--our means of dealing with the world) have been indirectly influenced by UFOs... From this perspective, of course, the question of whether UFOs are physical objects or not becomes immaterial, but we're still faced with a potentially rewarding scientific payoff.
Finally, I don't think UFOs (or their apparent occupants) should be taken at face value. The popular notion that alien are here to cross-breed with us, for example, seems to be a knee-jerk interpretation fueled by science fiction media. _But that doesn't negate the fact that a lot of people have had documented medical anomalies crop up consistent with their belief that this is indeed what is happening to them_.
Carl Sagan and others have told us over and over how strange alien contact will be. The situation we have now, it seems to me, is just strange enough that it might be for real (on some level, not necessarily "extraterrestrial").
Here are what I personally consider "essential" books on the subject:
"Flying Saucers: A Modern Myth of Things Seen in the Skies" Carl Jung
"The Invisible College" "Dimensions" "Forbidden Science" Jacques Vallee
"Confirmation" Whitley Strieber (fascinating and very sober)
"Above Top Secret" Timothy Good (touches on conspiracy theory, but also
demonstrates quite clearly that at least some UFOs are decidedly physical
objects)