University of Zurich performs an experiment that rewards participants in Bitcoins:
https://docs.google.com/forms/d/1IrJJn7Th9veghxfirrj3aQqx23nhDBhUIBGspfaybS4/viewform

That's probably the first time Bitcoin is used for scientific research. Bitcoin is a great choice as it allows for anonymous incentives.

Reddit discussion:
http://www.reddit.com/r/Bitcoin/comments/2pzc4h/play_a_game_earn_bitcoins_for_science/