This is the method that has worked for us and a few others that we have confirmed solid—if you know of any shortcuts or another way to enable MMS, let us know in the comments. Update: If you’ve been having issues, Giz reader Justin adds some additional steps (now numbered 3 and 4) that he says has worked for him and several others. Let us know it goes.

What You’ll Need
• iPhone 3G running OS 3.0
• Another AT&T phone (non-iPhone)
• This carrier file
• SIM ejector tool (or paperclip)

Make sure that you have carrier testing enabled in iTunes before proceeding:

 Step 2: Press Windows Key + R to open the run dialog. Enter in cmd then click OK

Step 3: Enter the following command into the Command Prompt window.

“C:\Program Files\iTunes\iTunes.exe” /setPrefInt carrier-testing 1

Step 4: Connect your iPhone and click to launch iTunes from your Start Menu.

Step 5: Select your iPhone from the list of devices on the left then hold down the Shift key and click the Check for Updates button.

Step 6: Now you can now select your .ipcc file as it is not greyed out

Prep Your iPhone
1. Download the carrier file.

2. Connect your iPhone to your computer. Open iTunes, and option or ctrl click (depending on whether you’re Mac or PC) “check for upgrade” which will open up your file browser. Select the .ipcc file. This is just a carrier file, it doesn’t do anything to your OS or data. Uploading it to your phone will just take a couple of seconds.

3. To make sure the update worked, go to Settings->General->About and look for “Carrier.” It should say “AT&T 5.”
4. Then go to ettings->General->Network->Cellular Data Network. It should say wap.cingular in the APN box, WAP@CINGULARGPRS.COM in the Username and CINGULAR1 in the Password field. Reboot your phone (you can do this after you take the SIM card out).

The Workaround

5.Take your SIM out of your iPhone and pop it into a phone that’s capable of MMS. Make sure it’s registered to your account on AT&T’s site (go into your account manager), replacing the iPhone as your listed phone. You might have to do this manually. I made a couple calls with the phone to make sure it registered

6. Go here, to AT&T’s MediaNet site, and register your phone number. You’ll get an SMS with a 4-digit code to confirm. Punch it in at the website.

MMS, Baby

7. Put your SIM card back in your iPhone. MMS should be working now! It’s kind of pokey (about 30 seconds to send a picture) and it’s dropped a message or two, but we were able to send pictures to people on multiple carriers and receive video from a phone on T-Mobile. It definitely works, and works pretty well. The interface for playing back MMS video (pictured up top) is slick, too.

8. Wonder how you ever did without it.

Word of Caution

We’re rocking an unlimited family messaging plan, so we’re not worried about any charges for blasting out tons of MMS messages. If you’re worried about account weirdness, you might wanna hold off. You could always ask your local AT&T guy to make sure you’re not getting hosed, just tell him you’re a developer (you’ve got iPhone 3.0, after all). Also if you’re squeamish about unofficial OS files, obviously.

Big thanks to Scratic, who showed this method to us. If you know a better way, let us know!

©Gizmodo

Before you can follow these instructions you must have a jailbroken iPhone and you must be on the 04.26.08 baseband(modem firmware). This means that you must be running the 3.0 firmware and have used PwnageTool or RedSn0w to jailbreak.

To find your firmware and modem firmware(baseband) versions you can follow this tutorial. If you are not on baseband version 04.26.08 then you need to upgrade to OS 3.0 via iTunes.

If you are on T-Mobile remember to turn off 3G before starting…

Step One
Press to launch Cydia Installer from your SpringBoard.

Step Two
Press to select the Manage tab at the bottom of the screen.

Step Three
Press to select the large Sources button

Step Four
Press the Edit button at the top right of the screen.

Step Five
Press the Add button at the top left of the screen.

Step Six
Enter http://repo666.ultrasn0w.com/ as the source url and press the Add Source button.

Step Seven
Once the source has been added press the large Return to Cydia button.

Step Eight
Press the Done button at the top right of the screen.

Step Nine
Press to select repo666.ultrasn0w.com from the list of user entered sources.

Step Ten
Press to select ultrasn0w from the list of packages

Step Eleven
Press the Install button at the top right of the screen.

Step Twelve
Press the Confirm button at the top right of the screen.

Step Thirteen
After installation completes successfully press the large Return to Cydia button.

Step Fourteen
Now press the Home button then power off and power on the iPhone. You do this by holding down the power button for 3 seconds then moving the power slider that appears to the right. Press the power button again to turn on the phone.

Step Fifteen
You should now be able to insert the SIM of your choice!

***THANKS: A big thank you to all the members of the iPhone Dev-Team for all their hard work! It is much appreciated by all.

Step One
Create a folder on your desktop called Pwnage

Download RedSn0wfrom here and place it in the Pwnage folder. Likewise, download the latest 3.0 firmware from below and place it in the same folder.

3.0.0 (3GS): iPhone2,1_3.0_7A341_Restore.ipsw

Extract the RedSn0w executable from the zip file to the Pwnage folder.

Step Two
Connect your iPhone to the computer and launch iTunes.

Select your iPhone from the list of devices on the left. Now hold down shift and click the Restore button. Restore is preferred as it won’t create any wasted space on your iPhone.

Navigate to the Pwnage folder on your desktop and select the firmware ipsw. Click the Open button to continue.

Step Three
Once iTunes has finished updating your iPhone to the desired firmware you may launch redsnw0w.exe from the Pwnage folder on your desktop.

Step Four
Once RedSn0w opens click the Browse button

Step Five
Select the firmware ipsw we placed in the Pwnage folder on our desktop then click Open

Step Six
Once the firmware has been verified click the Next button to continue.

Step Seven
Make sure Cydia is selected and click the Next button.

Step Eight
RedSn0w will now instruct you on how to put your iPhone into recovery mode. Disconnect you iPhone 3GS from the computer then power it off. Then hold down the Home button while reconnecting the device to the computer. Don’t let go of the button until RedSn0w detects the iPhone and begins installation.

Step Nine
Your iPhone will now reboot

Step Ten
RedSn0w will then begin uploading the new RAM Disk and kernel.

Step Eleven
Once this is complete you will be notified that RedSn0w is done. Click the Finish button. When your iPhone finishes rebooting (5 minutes or so) it will be jailbroken with Cydia on the SpringBoard.

it will then continue the process on your phone for the next minute or so and once it reboots your ready to roll.

iClarified

This is a preliminary jailbreak and thus some apps such as Winterboard will not work. You may want to consider waiting for the jailbreak release from the iPhone Dev-Team if this is important to you.

This tutorial should work with Windows XP, Vista and 7.

Step One
Open your web browser of choice and navigate to http://www.purplera1n.com. Click the Windows logo at the bottom of the screen.

Step Two
When prompted save the download to your desktop

Step Three
Double click the purplera1n.exe file from the desktop to launch the application

Step Four
Click the large make it ra1n button

Step Five
You iPhone will now be placed in recovery mode. You will see a picture of GeoHot that replaces the regular recovery mode screen on your device.

purplera1n will run and then your device will reboot.

Step Six
Once your device reboots you will see a new icon on the SpringBoard entitled Freeze. Press it to continue.

Step Seven
Once Freeze opens tap Install Cydia.

Step Eight
Once the Cydia installation has completed you must reboot your iPhone.

Step Nine
When you iPhone has rebooted you can run Cydia. Let it do all the necessary updates then follow our Unlock tutorial to finally unlock your iPhone 3GS.

NOTE*: To remove the Freeze icon from your desktop you can install CyDelete from Cydia then use it to delete the application. We will post a tutorial on this shortly.

THANKS*: A big thanks goes to GeoHot for his work in making this jailbreak possible. Also thanks to others who contributed such as chronic and the dev-team and to Mateen for the nice screenshots!

iClarified