Design Contests
What good is an embedded system project if you can't show it off?
Circuit Cellar is constantly running design contests with cash prizes (something like $3000 for first prize) sponsored by electronics manufacturers.
The Emhart/NASA design contest has some large prizes (hybrid vehicle or $20000!) for really just an idea with drawings and a description.
NCIIA Grants are awarded for a variety of innovative and entrepreneurial activities.
No money, just reputation for getting your project on Hack A Day.
The International Aerial Robotics Competition requires you to build an unmanned aerial robot.