If you struggle to sell it online, you can use
http://www.orangerecycle.co.uk/ and get £260 for it. If you print out the details of your order etc. you can actually take it into the orange shop in the and get your cash for it.
I'd still wait it out mind you, as new iphone won't start shipping for at least two weeks, which is better than the 3 months it normally takes after WWDC.
QUOTE(Scott_Gillan @ Jun 8 2010, 12:28 AM)

be hard to sell that now as the new 4g Iphone is going for £200 in the USA
Don't think that's correct, they would never sell them that cheap. You might be thinking of the 3GS which Wallmart are selling for $100.