if you have either an xbox or a ps3 with network connectivity then I would say use
tversity.
http://tversity.com/
Brilliant bit of software and free.
Id like to be able to stream films/tv to this if possible from a computer. What would be the easiest/cheapest way to go about this?
http://www.overclockers.co.uk/showproduct.php?prodid=HD-269-WD&groupid=701&catid=1240&subcat=911
Should do the job for you, easy if not the cheapest
If you have a PS3 then I find PS3 Media Server far better than TVersity for streaming.