Do you want to make a game and don't know where to start? Take a look at the new Popfly Game Creator! It's a new module to create casual games on Silverlight, starting from scratch to the 18 available templates. The system is complete and good enough though it's in a starting phase. Take a look at:

www.popfly.com

More at John Montgomery's blog: http://blogs.msdn.com/johnmont/archive/2008/04/30/the-new-popfly-game-creator.aspx

Watch some videos by Adam Nathan, showing how to create a game from scratch. 

Create a new game!

Some games with almost any code