Don't know if this has been posted before but if you're after a new laptop / netbook you could buy a refurbished one from PCWorld / Currys etc and get a trade in on an old one.
£150 for a working laptop under 4 years old
£100 for a working netbook
£50 for anything over 4 years old or not working, needs to have charger and battery (this one sounds like the most value for money to me)
The trade in laptop / netbook needs to be one of the following brands
* Ei Systems
* Packard Bell
I was sure they offer a tenner towards postage of your old stuff too, but I may have been dreaming as I can't find that particular line again.