Xbox Media Center is no longer for just the XBox. It’s UI is slicker than MythTV’s Frontend for playing music, videos, and showing slideshows of pictures. (It’s weather applet is also much nicer…) If you have an existing Ubuntu 9.10 based system, the PPA:team-xbmc repository makes it dead easy to install xbmc on a ubuntu computer with the following commands:

sudo add-apt-repository ppa:team-xbmc
sudo apt-get update
sudo apt-get install xbmc
sudo apt-get update