If you watched the Mix keynote, I am sure you saw the very cool Silverlight Momentum video that shows off a lot of the cool apps we have already seen in Silverlight.
In case you missed it, here it is:
[Mobile] [Progressive download] [streaming]
[4M CBR] [720p] [640x360]
Read the complete post at http://blogs.msdn.com/brada/archive/2008/03/10/cool-silverlight-momentum-video-posted.aspx