The carrier settings update from AT&T arrived at around 10:30 a.m. PT on Friday, and I've spent the better part of the morning testing the new service. Here's what to expect when you take MMS for a test drive of your own.

Getting the update

Apple has posted some easy-to-follow instructions on enabling MMS on the iPhone 3G and 3GS (as well as a reminder that the original iPhone doesn't support the new functionality, though owners of that model can view, via AT&T's View My Message Web site, any MMS messages they receive). But here's a quick summary of what you need to do to get MMS capabilities on your iPhone:

• Make sure you're running the iPhone 3.1 update.
• Connect your iPhone, go to iTunes, and check for software updates. You should be notified that there's an update to the carrier settings for your iPhone.
• After installing that update, restart your phone by turning the power off. (Hold down the power button on the top of the device, and use the slider to power off when prompted.)
• Turn the power back on, and you should be good to go.

You'll know that the update installed properly by going to the Messages app. The field for entering text messages should have a camera icon just to left. If not, disconnect and reconnect the iPhone and try again, consulting Apple's MMS troubleshooting guide for any additional assistance.

Using MMS

So now that you have the ability to pester friends and contacts with photos of your cat, how do you go about doing it? From the Messages app itself, just tap that camera icon; your iPhone will prompt you to either take a photo or choose an existing image from your camera roll. If you opt for the former, the camera will launch, and you tap to take the shot. You'll see a preview image with options to either use the photo or retake it if you're dissatisfied with it.

Once you've selected an image, a thumbnail version of it will appear in one of Messages' dialogue balloons. You can also type a text message to accompany the picture, though once you hit send, the image and text appear in different balloons.