I have a 3G with 3.0.1 firmware, on AT&T. A few weeks ago I installed a package through Cydia that "unlocked" the MMS capabilities in the Messaging App and altered my network settings to enable sending/receiving MMS on AT&T's network, but I still could not send or receive MMS messages. I always got an error message that it couldn't send. Fast-forward to today, and I can now send and receive MMS. Under Cellular Data Network (in Settings on my phone) my settings are: Cellular Data: APN: wap.cingular username: <blank> password: <blank> Visual Voicemail: APN: acds.voicemail username and password: <blank> MMS: APN: wap.cingular username and password: <blank> MMSC: http://mmsc.cingular.com MMS Proxy: 066.209.011.032 MMS Max Message Size: 614400 MMS UA Prof URL: http://wap.sonyericsson.com/UAprof/W800iR101.xml Has anyone else had luck with MMS working already?? I wonder if AT&T has already "flipped the switch on" and are just waiting for the software upgrade from Apple to enable the iPhone's MMS features in Messaging.