Ok here is how to make the above work on t-mobile! [note this may work for other providers however I have only tested it on t-mobile USA]
Once your iPhone is jailbroken and unlocked you will want to do the following
Make sure Data Roaming is turned on and 3G is OFF then go into Cellular Data Network.
From here enter in the following
MMS Proxy 126.96.36.199:8080
MMS Max Message Size:
MMS UA Prof URL:
Now reboot your iPhone and you are good to go!!! You will now have a little camera icon next to your message window on the sms/mms application.
AS ALWAYS TRY THIS AT YOUR OWN RISK!! THE CHANCES OF SOMETHING GETTING MESSED UP WHILE DOING THIS ARE VERY VERY SLIM HOWEVER IF YOUR PHONE BREAKS ITS NOT OUR FAULT!