Whats worth doing. The pinnacle boxes which stream off your pc over the network cost just over £100 which is less than building a htpc but are the pinnacle boxes anygood - any advantage of a htpc over a pinnacle box:
http://www.pinnaclesys.com/PublicSite/us/Products/Consumer+Products/Digital+Media+Adapters/Digital+Media+Player/ShowCenter+200
http://www.pinnaclesys.com/PublicSite/us/Products/Consumer+Products/Digital+Media+Adapters/Digital+Media+Player/ShowCenter+200