One project I want to do when I have a little break is to get either an Epia 5000 or maybe an ME 6000 and attach it to the back of a flat-screen. It should be relatively simple to do.
The idea behind it is to have the board chug along behind the screen invisible, silent and slim. I imagine that something like that would make a very good net cruiser, or a living room computer where silence is more important than CPU horsepower. If I end up building it I'll be sure to put up some pics.