One of great features of the new iPhone OS 3.0 is the ability to send MMS. Here is the video instruction on “How to Send MMS on iPhone 3.0 or iPod Touch“. Please remember that your carrier must support MMS and you may be charged extra for MMS messaging if you do not have a plan.
How to Send/Receive MMS on iPhone 3.0 OS
If you are not interested to see the video or if Video is off-line, here is a detailed step-by-step instruction on How to Send/Receive MMS on iPhone 3.0 OS
And here is a proof that MMS and Tethering is working on Airtel, India