iPhone USB / Bluetooth Tethering With Linux

In order for tethering to work, your iPhone must actually have the tethering option enabled. This depends on your network carrier and contract. For iPhone 3.0 OS you can also just install a so-called mobileconfig profile which enables tethering, but this in a gray zone legally. For later firmwares your iPhone additionally needs to be jailbroken and a system file patched which is surely not everybody's thing.