MacRumors.com

A number of AT&T iPhone users around the United States are reporting that MMS is already working in advance of the September 25 date AT&T has officially announced as the MMS go-live date. According to accounts from forum members and across the web, MMS has started to work for some AT&T iPhone users with iPhone OS 3.1 out of the blue, requiring no action on their part to get it working.

Other forum members have followed instructions provided by Krillr.com to manually update a carrier settings file on their iPhones via iTunes, a method similar to hacks reported earlier this summer. Some have had success while others have not, though the ability to get MMS working appears to be more likely in some locations than others. Members have reported working MMS after applying the carrier file in California, Washington, Florida, Texas, and more, while others in Colorado, New Jersey, and other states describe that this method has not worked for them.

One side effect experienced by some who have tried this method is that visual voicemail ceases to function. Others report that MMS messaging will only work after the iPhone's Wi-Fi radio is turned off.

Another potential factor in enabling MMS functionality before the official go-live date is the selected messaging plan. Those on an unlimited family messaging plan appear to have better chances at success in enabling MMS than those on a standard iPhone messaging plan.

While the methods that require the use of a modified carrier file to enable MMS do not technically appear to be jailbreaking or hacking your iPhone, following these instructions may have some negative consequences that are yet unknown, so iPhone users should proceed with caution in following them. With AT&T's official roll-out of this feature in under two weeks, it may be less risky to wait.