This is the first Silverlight-based game I've seen on the web, and it's pretty slick.
Thanks to fellow evangelisto Tim Heuer for "Zero Gravity", the result of 4 weeks with a team of 5 (designers, developers, animators/artists).
The team used used Expression Design, Expression Blend 2 and Visual Studio “Orcas” to develop the game.
Give it a test 'fly' at http://www.ltbennett.com.