I was listening to a podcast a few years ago and someone jokingly said "why not attach computer parts to a board and hang it on the wall". I thought, hey that's not a bad idea, and while I'm at it, let's make it a work of art. I call the build the Mona Server and it is 100% functional. All the wires are run inside the wall, and I installed a couple of USB ports in the wall so I could hook up a printer to it. Currently it is running Windows Home Server 2011 and I use it to store all of my music, scanned books and documents, as well as to backup my computers around the house. It is also running a SQL Server on it which is used to log data from my salt water reef tank. One thing I love about it is that it is quiet, the only thing you hear is the CPU fan! The complete build is documented here...
http://homeservershow.com/the-mona-server.html
Cheers,
jvk