Apple Has release software version 4.0.1 for iPhone 3G and 3Gs ,  for the long run till now we find the unlocking solution these two version ,

We can now jailbreak any iPhone (including the iPhone 4) on iOS 4 . Before Unlocking make sure your device is activation on iOS 4.0.0 or 4.0.1.

In store service takes about 30mminutes.

Cost $30 to unlocked and Jailbreak your iphone 3G or 3Gs 4.0.0 and 4.0.1

click here to see other version ability