Games
Improve your keyboard and theory skills:
musictheory.net
Whack a Note:
http://artsedge.kennedy-center.org/interactives/steprightup/whackanote/whackanote.html
Investigate these games:
http://www.musictechteacher.com/music_quizzes/music_quizzes.htm
Incredibox:
More games:
http://cornerstoneconfessions.com/2012/08/the-ultimate-list-of-online-music.html