iPhone Dev Team delivers on New Year's Day and unlocks iPhone 3G devices

Many people may ask why you would want to try to unlock your iPhone 3G and I think the main reason is so that you can use it when you travel outside of the country where you purchased your iPhone. Looking at some of the comments on the Dev Team blog it looks like usage in other countries is the most popular need for this capability.

If you are in the U.S. and you don't travel internationally then I don't see why you would really want to unlock it and use it on the slower T-Mobile network. I have an original iPhone that I use with my AT&T and T-Mobile SIMs, but most people only have one wireless carrier. I am perfectly happy with my original iPhone and won't be upgrading to a 3G to unlock and use it on T-Mobile.