There's someone selling a perpetual motion machine - that requires "no external power source whatsoever" - on ebay. I can't believe that ebay let 5 morons bid on this thing. Definitely read the absurd second paragraph description. Thanks Metafilter.
It's great how people that sell crap like this insist on "Serious buyers only" in their posts. Seriously failed physics, maybe. Why didnt the original owner just keep it to power his house forever, for free?