Despite its statement that MMS would be available to iPhone customers beginning on September 25, AT&T began a gradual rollout of the coveted feature in select markets starting on Friday.

According to a report on The Consumerist “seemingly random iPhone users, from Manhattan to Idaho” have reported that MMS suddenly began working on their iPhones beginning on September 11. There’s a nine-page (and growing) thread at Howard Forums starting by iPhone users whose MMS is now working.

Reports vary, but the common thread is iPhone OS 3.1 and AT&T carrier bundle v5.0 or 5.1 for MMS to work. You can check your carrier bundle version by tapping Settings > General > About > Carrier.

Mediaite surmises that the surge of MMS activations is due to “AT&T working through the process of removing the opt-out codes that have blocked MMS from working on iPhone accounts since the 3.0 release.”

I reported here that AT&T began testing MMS in Washington around August 3.