It's a great camera for the money it was back when it first came out. I got one in 2005 I think it was – 600ish quid back then. So long as it's in good condition – it's gotta be worth it. I've used mine a lot over the years – took it travelling around the world where I used it almost every day for a year and it held up fine.
Advantage over more expensive models is it doesn't weigh as much. Main disadvantage is general pic quality (although for the £ it's good!) but this can be improved by a better quality lens – quality of lens can have more effect than number of mega pixels.
Also in ISOs over 400, pics can get a bit grainy (refered to as 'noise') with the cheaper Canons but you'll only really notice this in low light conditions, over all you can't go wrong with the canon and nikons at the cheaper end of the market.
(Only Canon I'd avoid is the 50d – too many mega pixels crammed into the sensor creating too much noise – hence grainy pics).