As promised, AT&T on Friday activated Multimedia Messaging (MMS) for the iPhone 3G and iPhone 3GS. Getting the new feature to work on your iPhone requires an update, available through iTunes. Simply plug your phone into your computer and click the Check for Update button.

The small update will download and install — that’s all there is to it. You should also restart your phone when the update has finished, just to be sure.

It’s quite easy to tell if MMS has been activated on your phone. Go to Apple’s messaging app and start a new message. You should see a little camera icon next to the text field. If you tap on the camera, it will ask you to take a picture or choose one from your library.