Tried that as well, but for some reason it would only go to an Alltel activation call, and obviously that woudn't work lol. So...
Ended up going through a decent amount of troubleshooting.
I turned on/off airplane mode.
Turned off data service, turned back on.
Reset Network settings
at the end, I did a complete wipe. Ok, so I have the phone JB, and forgot to NOT erase all settings and content.
Well, so the phone turns off, goes into restart, and the circular "busy" icon turns and turns for about ten minutes. I went ahead and held power + home button until the phone restarts. Apple logo comes on screen, and within a few mins the phone has restarted. All icons, etc., are there like there wasn't any content erased. Also, it gave me the activation message. A couple mins later, everything is working 100% again.