Here's the source to the WriteableBitmap sample I showed at Mix. The sample uses WriteableBitmap to take a "snapshot" of the running video to make a thumbnail. Click on the image below to run the sample. When running the sample, click on the running video to create a thumbnail. You can find the video for this sample here.
The demo shows the following new Silverlight 3 features:
· WrapPanel (new SDK control)