"Our dear friends in Plexipixel have created a nice Silverlight based game on Facebook. It is called Roshamboom! (http://apps.facebook.com/roshamboom).

Roshamboom! is inspired by David C. Lovelace’s extreme rock-paper-scissors concept called RPS-101.  The RPS-101 (http://umop.com) game got a ton of web chatter when it was released back in 2007 because it took David over a year to concept the game and produce the 5000+ outcomes.  The Plexipixel folks thought it would make an ideal (and silly) turn-based game for Facebook.  Plus, it allowed them to practice some Silverlight skills."

Barak Cohen @ Microsoft