Silverlight 3 Media Viewer Web Part for SharePoint
Some time ago, I created a Silverlight 2 variant on one of the Silverlight BluePrint for SharePoint samples. Since a few weeks people start to request a Silverlight 3 version. You can download the Silverlight 3 version of the web part here. The zip contains the source code for the web part and the Silverlight application. It also contains a .wsp that you can upload and deploy to your SharePoint sites.
If you want to know how to install Silvelright 3 and what you need to know before using Silverlight 3 with SharePoint, read this post.
If you want to read more details about this web part, read this post.