Little update if anyone's interested

I ended up going with a couple of 320GB external drives in the end - one to download to and one to back up to....
(PC World have got a pretty good deal on WD 320GB external hard drives atm if anyone's interested )

I have to say though.... I do notice quite a difference in Limewire's performance when I download to an external, as opposed to my pc's main drive.... There's quite a bit of crashing and freezing tends to go on - which I can't say I ever experienced when I was downloading to my main drive.
Having said that though - I kinda feel 'safer' downloading to an external and not my pc hard drive. Though maybe that's just me....

Stating the obvious here - if something major happens with your pc and you've got no copes of anything.... well you're up the proverbial creek without that all important paddle!
I find it quite unbelievable how many people *still* don't back up - then whinge and moan when all their documents, photos and music are lost....