The US Copyright Office has approved a request to permit cell phone users to "unlock" their cell phones. The decision will allow cell phone users to change carriers without having to buy a new phone.
The new rules will take effect Monday and expire in three years.
In granting the exemption for cell phone users, the Copyright Office determined that consumers aren't able to enjoy full legal use of their handsets because of software locks that wireless providers have been placing to control access to phones' underlying programs.
So, as long as your moving to a new carrier with the same technology, you will be able to "unlock" your cell phone and use it on the new network. The obvious exception is Sprint/Nextel, as they use a different format than Cingular, T-Mobile, Verizon, et al.