The LG CU400, available on AT&T, operates on its 3G UMTS network. It has quad-band support, VGA camera, Push-to-Talk, mobile email, Cingular Video, and Bluetooth. You can also access XM satellite radio and MobiRadio, which helps make up for its absense of a MP3 player.

Reviews:
Cnet
PhoneArena
InfoSyncWorld

Resources:
AT&T Support
LG Official Site