UPnP Media Servers have been around for awhile now. You can store all kinds of media like photos, music and video files on them. It is just a convenient way to store all your media files and have them accessible from anywhere on your network. Of course, you do need a UPnP client to access these servers. These clients are available on many hardware and software platforms but so far none for the Apple TV. Well, thanks to Bruno Keymolen, the Apple TV is no longer left out.
Introducing Home MediaCloud, a UPnP Client for the Apple TV. Now, not only can you access those media files from your PS3, Xbox 360, Macs and other devices, you can do it via the Apple TV too.
Like most hacks available here, you do need an ssh-enabled Apple TV (with software version 1.1). You also need to install a few libraries in order to get it to work. And, lastly, to support a wide range of video formats, it is advised that you also install Perian and Flip4Mac on your Apple TV.
Any questions or suggestions, you can contact Bruno directly.