AT&T has finally enabled multimedia messaging ( MMS ) for both iPhone 3G and 3GS and users are waving of happiness. The feature became available right after 1 p.m. Eastern Time and there’s also a support page available for the new feature.

iPhone MMS requires iPhone OS 3.1 and some setting update downloadable from iTunes.

To activate it, you need to have iTunes 8.2 or later, connect your iTunes to your computer, open iTunes, then select your phone from the list of Devices and click “Check for Update.” After that click “Update Settings,” let it download and install the update, then restart your iPhone.

After that, try to create a new text message and a camera icon should show up on the left of the text field. This way you can send both photos and videos via multimedia messaging.

Unfortunately, the first-gen iPhone didn’t get the feature and it will probably never do.