Its only been 2 hours since you posted
£500 will only get your a budget laptop, but for the uses you suggested that should be fine. You could try the Dell outlet (
www.dell.co.uk/outlet) if you don't mind a refurbished/canceled one (I've had a few and been pleased), you should be able to get a good one for around £500 there.
You can always try the main Dell site and get a 510m for around £500, although I would avoid the 1150's unless you don't mind a large laptop. Acer do have some cheap deals at the moment, but support seems to be terrible.