I heard about this story last year and just found an article on the Globeandmail.com detailing the end result. A man started with a paperclip and intended to trade up until he had a house. Amazingly, it has only taken him 14 trades. Starting out in Belcarra, BC, Kyle MacDonald has managed to trade a part in a movie for a house in Kipling, SK. That aspect I don't really understand; how do you trade a role in a movie that you didn't have in the first place for a tangible, inhabitable house?
In any case, the story is interesting and you can read about it in the Globe and Mail here, or on the guy's blog here. Everything starts with one small step, or so they say.