Hong Kong based Gadget shop Brando just informed us that they now sell a small circuit card that supposedly unlocks the iPhone 3G and many other phones on the SIM card level.
The i-Smartphone 2008 sells for only $20.50. The thin-film card is put together with the SIM card you want to use the iPhone 3G on in the slot.
This sounds way too simple and low-cost that it is hard to believe that this would really unlock the iPhone 3G.
After some research I found a thread on Hackint0sh that discusses the i-Smartphone card and similar solutions that are sold under names like X-Sim, RebelSim, and YesSim.
Some users report that they got GSM voice working, but actually no 3G data services are working with the hacked SIM tool on the iPhone 3G.
As it looks the best bet on a completely unlocked iPhone 3G is the iPhone Dev Team and their PwnageTool.