One of the features I've wanted for a while now in Media Center is the ability to easily jump around within media. I have a bunch of family home videos on my machine, and it can be frustrating to navigate to particular moments that I want to show to family and friends. To compensate for this, I wrote a plug-in, PositionChangerAddIn, that allows me to use the remote control for Media Center to navigate to different positions within the currently playing media (recorded TV, video, audio, etc.), using the number buttons on the remote control to enter time codes that Media Center then jumps to, as well as using the arrow keys to set and jump to bookmarks in the media. Some folks asked me how I implemented it and if I could share the add-in with them, so I decided to write an MSDN article about it. The article went live today at http://msdn.microsoft.com/smartclient/default.aspx?pull=/library/en-us/dnxpmce/html/positionchangeraddin.asp (new article at http://msdn2.microsoft.com/en-us/library/bb643809.aspx). In addition to learning all about how the add-in was implemented (and how add-ins are implemented in general for Media Center), from that page you can download both the source code for the add-in and a complete installer to get up and running with it. Directions for using the add-in are included in the article.
Hope you like it. If you do, please let me know by giving the article a good rating... if it does well enough, I might be inclined to write some more about MCE development ;)
ps Note that the add-in is only for use with Media Center 2005. It will not work with previous versions, and it might not work with future versions, at least not without some modifications here and there.