Modify the Apple TV Menu

EricIII has released ATVFiles which adds a 'Files' Menu to the Apple TV Default Interface. The files section can be mounted to an NFS or AFP share on your network to share movies and music across the network without using iTunes.

Although EricIII has not released source code, some other developers on the InsanelyMac Forums have released the source code of their plugin which does something similar, and also one that can exit the ATV Finder app. You will need to download XCode to compile the source code.

Check out this post on InsanelyMac Forums for More Info