Stumbled on 2 more projects you can do for the Raspberry PI, first one is basically making an arcade gaming system. The second one seems to be still in the works, but is a weather station.
http://lifehacker.com/how-to-turn-your-raspberry-pi-into-a-retro-game-console-498561192
http://www.weather.dragontail.co.uk/index.php?page=station_setup