MythTV for iPhone allows you to watch your TV shows on your MythTV DVR on your iPhone (or iPod Touch).
The software allows you to browse your recorded shows, and look at show details. You can stream any recorded show to the iPhone (or iPod Touch) wirelessly. The technology behind it is MythTV (The Open-Source DVR), PHP for the backend, Smarty and iUI for the frontend. http://code.google.com/p/mythtv-for-iphone/