Homegroup device

I highly doubt it but is there any devices you can buy that could connect to your homenetwork so you can stream movies from a pc for example to a tv without having to shift files between computers? Just like a regular laptop but its only purpose is to play movies on a tv.

I use my xbox and the program vuze to stream

Use an old computer, a 360, PS3 or something like an Apple TV that's dedicated to streaming.