FYI: iPhone 3G can--- be unlocked yet (check yellowsn0w section)
Edit: Did you know about Yellowsn0w?
As you should know by now, the iPhone 3G cannot be unlocked yet.
As soon as the unlock tool be ready, we'll let you know. So, please don't start new threads about it.
Also, regarding to the *SIM solutions, just don't even try it, because they may do very undesired results. You can check this threads if you want:
[*Sim] [3G] Results from data observation - Stay away from *sim solutions.
[3G] xSIMs and friends (dual SIM proxy family) - don't bother