It's quite impractical to have a pc set up in my bedroom, I am building a new one for gaming but that's another story.
All I really need is a basic PC for when I don't have access to my gaming rig and just want to browse the internet or do a bit of work, I'm leaning more towards the netbooks now however.
This doesn't make a huge amount of sense to me. For your requirements you could easily build a sff pc that's smaller and cheaper than a ps3. For even less money you could pick up a second hand Compaq Deskpro off of ebay that's about comparable in size to a ps3 (maybe even smaller) that would easily out perform it in Linux. I'm sure they're around £50. It would probably have an xp license slapped on the side too.