PowerPlaylist adds a custom Start Menu strip with up to five tiles to Windows Media Center in Windows Vista. Each tile represents an audio, slideshow and / or visualization combination which will start when the tile is selected. PowerPlaylist is very customizable by the consumer using the PowerPlaylist Editor, including the title of the custom Start Menu strip and the name, image, audio source, slideshow folder and visualization for each tile. It's over on CodePlex.com so has full source code available with the Microsoft Permissive License.

Check it out at http://www.codeplex.com/powerplaylist.