This is the first iPhone 3G Jailbroken Custom firmware of iOS4.1
This Firmware is Custom, which means it will not update your baseband and you will be able to unlock your phone after upgrade. The firmware is made with PwnageTool 4.0.1 with new firmware bundle which is still private. It will need official SIM for activation, I made it this way because you will have no issues with Push and Youtube certificates, and also with automatic update of carrier bundles. If someone request i can make Activated one as well.
But enough talk, here are the links. (file is on 2 parts because of hosting limitation of 200 MB)