I am definitely interested in upgrading my current O2 iphone to the new 3g one on July 11th. The only thing I am unsure on is when to sell my current one - ie. will O2 require the current one in order to get the upgrade? I assume the sooner I can sell it on eBay the better as the price will drop significantly. I guess what I am asking is should I unlock it and sell it now or wait till July 11th for fear that O2 will require it as proof or something that I am a current iPhone user.