Yes Luc, it's a risky gamble at best. Whether one could come away with a workable idea all depends on the people there and whether or not you could spend time with someone to really pick their brain.
I do know that I bought Aaron's "Ignition Secrets" videos quite a while back and I was able to not only build a true plasma ignition system, but I improved on it beyond what Aaron demonstrated. So slim as the chance might be, there exists a possibility to acquire a little piece of knowledge wherever you can find it.
I attended the GlobalBEM conference in Boulder last year and did get to meet quite a few people including Russ, firepinto, gpssonar, Rav, ZeroFossilFuel, Moray King, Sterling Allan, Ed Mitchell, bussi04 and quite a few others. So in that respect, it was nice to know what people where thinking and trying to build. Do I have a free energy device to show for all it? No, but I do have people to bounce ideas off of that I really didn't before.