I have an iPhone 4 Baseband 3.10.01 and iOS 4.2.1....its locked by postpaid (like AT&T)...and i want to install cydia in it...is there a way i can Jailbreak and Unlock it...w/o changing the Baseband?
You can get the jailbreak guide for an iPhone 4 from absinthejailbreak.com and to unlock your iPhone 4, You can visit Simpleunlocking.com and get the remote unlocking service. This method of unlocking is safe, simple, affordable, quick and permanent. Good luck mate.