I'm pretty much a sucker for human-powered anything but the quest for the Sikorsky Prize is just too cool for words. The nitty-gritty details:
"The American Helicopter Society (AHS) has promised $250,000 to the team that can build a human-powered helicopter. All it has to do is hover for a minute, reach a height of 3 meters (about 10 feet), and stay in a 10-meter box.
Turns out, that's harder than it sounds. The prize has been unclaimed for more than three decades." The rest of the article is here.