Rogers Wireless in Canada has had MMS enabled on iPhones since 3.0 software came out (July 17th 2009)... and has seen no negative impact on the network. In fact, because MMS is such an old technology and only allows messages up to 300k to be sent (600k on WAP 2.0, but not on iPhone), images must be compressed and shrunk. For this reason, most users will still prefer to attach a photo or sound clip to an email and send it that way... I'm really not seeing a reason why AT&T has been so slow to join the game.. and ontop of that, why they're seeing such a huge impact to their network. MMS was never originally included on iPhones because of it's limitations and backwards thinking.. Apple assumed people would smarten up and just use email. They caved and introduced MMS in software 3.0 because of user complaints.. but I'm still not seeing why anybody would use MMS nowadays.