A great Instructable about using the Adafruit protoshield inside a four-contestant gameshow system. RoysterBot writes:

If you have ever watched a TV quiz show you have probably seen contestants trying to press a button in order to win a chance to answer a question. The contestant’s quick reaction time results in some kind of light and/or sound indicating victory. This is a practical way to choose the next focus of the game’s activity and it adds a bit of excitement to the process. So when the holiday party planning committee decided to have a trivia contest I decided to build a quiz contestant lockout system to add an extra dimension of fun to the festivities. This would help the planning committee’s mission of creating some entertaining activities for the event.

The minimum requirements were to have a system with multiple buttons that contestants press for a chance to answer a question. The first one to press the button would lock out the other contestants. The system would need to have a simple way to quickly identify who pushed their button first. And finally the system would need to be reset for the next round.

Considering the venue of the holiday party (an upscale wine bar) I felt that the contestant buttons would be one of the most important features. They needed to be hefty and able to withstand abuse by hoards of “beverage enhanced” partygoers.