Geohot’s LimeraIn has been rolled out before its estimated time of release. Limerain can jailbreak iPhone 4 and all other previous iDevices on iOS 4.1 including previous iOS versions. Though it is little buggy at this stage for some idevices but it works for most. Here is the step by step tutorial to jailbreak iOS 4.1 on iPhone 4 using the Limerain.
Step 1: Download the Limerain.
Step 2: Plug in the phone and launch the limera1n.
Step 3: Click on “Make it ra1n”.
Step 4: Now hold the “Home+Power” button to go into DFU button.
Step 5: Keep holding the Home button, release the Power button.
Step 6: The iPhone is now in DFU mode, wait until Limera1n does its work.
Step 7: Limerain has done its work. Now your iPhone 4 is jailbroken
Step 8: Reboot your phone, lauch Limera1n on your iPhone 4 and select Cydia to install.
Step 9: After the Cydia is installed, you may uninstall the limerain.
- Limerain to jailbreak iPhone 4 [Official Direct Link]