Totally forgot about the iPhone 3G Vietnam Hardware Unlock
"Dong Ngo reports for Cnet on the hardware unlocking progress employed by local mobile shops in Vietnam. He writes about witnessing how Tuan Anh Do, a 29-year-old businessman who owns five cell phone repair shops, hardware unlocks the iPhone 3G.
First, a technician opened up the phone and stripped it to the motherboard. In his skillful hands, the device seemed much easier to dismantle than I expected.
The technician then extracted the baseband chip, the component that controls the connection between the phone and the mobile network, from the motherboard. (This is a painstaking task as the chip is strongly glued to the phone's motherboard. A mistake during this process could brick the phone completely.)
Once the chip was extracted, it was Tuan Anh's turn. He used a chip reader to read information into a file. He then used a Hex editor to remove the locking data from the file, and after that, the chip got reprogrammed with the newly altered file. Now it was no longer programmed to work with only a specific provider.
The chip then got reassembled into the motherboard, another painstaking process.
As a last step, the technician put the phone back together, and it looked like nothing had been done to it. However, the phone is now unlocked and can be used with any carrier's SIM.
Each unlocking job takes about an hour to complete and costs 1.2 million dong (about $80)"