UPDATE : iPhone 3GS has a different security feature which disables it from using any other firmware rather than the latest available. So, if you still need Unlock and Jailbreak, custom firmware (look in categories) is the only option we have. The following article is not recommended anymore. Thank you.
Geohot rules yet again! He was the one to have unlocked the iPhone first generation phone back in 2007 and now, he is back with more! This time it is iPhone 3GS that is unlocked and jailbroken by the hacking maestro …