The folks over at the iPhone Dev Team have successfully unlocked the iPhone 3G software to accept SIM cards from other carriers.
This was demonstrated by Dev Team member “Musclenerd” where he unlocked the AT&T iPhone 3G to work with T-Mobile network. The codename for the software is called “Yellowsn0w” and from the 4.22 minute video the procedure looks incredibly simple. Yellowsn0w will be released New Year’s Eve – just in time to start 2009 off with a bang and an open iPhone market!
Here is the video: