Visit Challenge.gov to participate in government contests and challenges for the chance to win a variety of prizes (monetary or non-monetary).
You may be challenged to solve a problem, make a suggestion, shoot and upload a video, create a logo, build an online game, invent something, and much more. A new challenge from Kids.gov, for example, calls for posters that answer the question, "How do I become President?" Find more details about this and other challenges.
Even if you don't have a solution for a specific challenge, you can share challenges with friends or sign up to show support for a challenge.