As we all know the xBox 360 can play video over a network but can be nighmare with what it chooses to play, the media center is a bit slow at times and if you have Windows Server 2003 etc you have to have a media center to stream it from the server to the 360.
I found myself in this problem, windows 2003 server to hold all my films, loads of none compatible videos etc
After hours of messing around I came across This
It streams video to the 360 from your 2003 server etc, converts video on the fly to WMV so you can play whatever you have and is so easy to setup and you don't need to use the Media Center part of your 360 to play videos, they show up under the "Videos" tab. If you have a Core 2 you can encode 720P video on the fly.
It fantastic and turns your 360 into a true standalone media center....
I have to say the 360 is one of the best "big boys toys" ever made!