Mal from CanDo Interactive is hosting a Blender game engine contest. The deadline is March 16th, and there's a nice lineup of prizes.
From the contest page:
This competition is being run to encourage developers ( or teams of developers ) to create fun, cool looking content for the Game Engine built into Blender.
With the release of 2.48, the GE has received a HUGE boost in terms of speed, functionality, and more importantly kudos.
More information on the Blender Wiki.