In fact there are various easy ways to unlock an AVR written with wrong fuses. Many enthusiasts have tried and suceeded in the ways they found convinient, including me. I have suceeded in the trick mentioned by " " on the third page of EDA board thread found here. "http://www.edaboard.com/ftopic323123-90.html
Sorry...that the link given is almost the same thread, but may be a different page as i have given it from my offline contents. While i was posting this, i coudnt acess the EDA board website. may be some technical server problems.