Apple's iPhone 3G and iPhone 3GS support multimedia text messaging, or MMS, and now that AT&T has finally activated the feature, iPhone users can start texting photos to their friends. If you're new to the world of MMS, here's how to get started:

Make sure the MMS carrier update is installed on your iPhone. Check out our TMO Quick Tip on updating for MMS to see how.

• Tap Messages
• Tap the new message button to start a new text chat, or select a chat you want to resume from the message list.
• Tap the camera button in the lower left corner of the chat screen and pick an image from your iPhone's photo library or take a new picture. You can include a text message with the photo, too.
• Tap Send.

Composing an MMS message (left) and receiving one (right)

You can also share images from your iPhone's Photo app. Tap Photos and do this:

• Tap the photo you want to send as an MMS message.
• Tap the share button in the lower left of the Photos app, and then tap MMS.
• Your iPhone will open the Messages application with your photo already in a new message. Just enter the contact you want to send the photo to and tap Send.

You can send images from the Photos app

If sending and receiving photos in text messages isn't your thing, you can disable MMS, too. Just go to Settings > Messages and switch MMS Messaging to Off.

You can disable MMS messaging

iPhone owners have been able to share photos as email attachments is ever since Apple first released the combination iPod and smartphone, but the addition of MMS means they can send -- and finally receive -- photos in text messages, just like other mobile phone users have been doing for some time.