I saw a post before about a Zune hack tha lets you play mpeg and DVR-MS. this is great for those who have already made our DVD collection into mpeg or DVR-MS (My movies just got DVR-MS suppport) to play on our Xbox 360.

http://lifehacker.com/software/conversions/hack-the-zune-software-to-support-more-audiovideo-formats-256728.php