updated 10:30 am EDT, Thu April 10, 2008
An Apple patent application from 2006, recently disclosed by the US Patent and Trademark Office, suggests that Apple at least once contemplated letting users pick from multiple carriers on an iPhone. The current American iPhone is tethered by default to AT&T and affiliates, forcing users to hack it if they want to operate on a choice of networks; under the scheme described by the patent however, network addresses for multiple carriers could be stored on a mobile device, and selected as necessary for the purposes of roaming. This somewhat reflects the way iPhone users can now choose Wi-Fi hotspots.
More unusual would be the ability to receive going rates for each carrier, effectively allowing on-the-fly comparison shopping. The patent specifically focuses on mobile virtual network operators (MVNOs), though, suggesting that Apple had no intention of letting users select a fully independent carrier. It has been rumored that the Australian iPhone could operate on any of the country's major GSM networks.