I like a lot of people have an unlocked iphone (not to be confused with a Jail broken one). So on installing the 3.0 update MMS was immediately available but I suspect, like me, for most it won’t actually be active (no little camera icon in Messages is an indicator if it’s working or not). If this is the case all you need to do is enter your MMS settings (a quick Google should provide you with the correct info – UK users can grab them here) via the steps below.
Access Point Name: general.t-mobile.uk
Data bearer: GPRS
Gateway IP (proxy) address: 126.96.36.199 (also 188.8.131.52)
Session mode: Permanent
MMS Message (Relay) Server URL: http://mmsc.t-mobile.co.uk:8002/
It’s worth pointing out that if you have an unlocked iPhone you don’t need to do any of the ipcc file hacking that a lot of the “beta” articles seemed to indicate. The MMS option should be alreay present and just need configuring. If you’re with an official carrier like AT&T or O2 etc the process may be completely different as it seems to require hacking the ipcc file to set certain values so your mileage may vary.