Reports that AT&T was going to offer a Micro SIM adapter to allow the use of the Micro SIM in devices that still use a full-sized SIM appear to be incorrect. Our sources tell us that AT&T will be using a two-in-one approach that is likely to be used by other carriers, as well.

The card that the SIM comes on is perforated in such a way that the SIM can be used in a standard SIM device or adapted to the Micro SIM format by taking advantage of the extra set of perforations, which cuts the SIM down to micro size. This two-in-one format appears likely to be the way that most carriers will deliver SIMs in the future.

We do still suspect that SIM to Micro SIM adapters will be available from other sources, but with this two-in-one format once adopted by carriers, the need for adapters should diminish as older phones are obsoleted or trashed. We expect most manufacturers to adopt the Micro SIM standard going forward, according to our sources in the industry, who claim that this is the format that carriers will adopt going forward.