No Phone/Data, Radio off -- Help!

Woke up this morning with no cell signal at all. I rebooted the phone, and it showed the date as December 31, 1999 and time as 3 AM. When I try to make a call, I get a message that the phone is in airplane mode, which it isn't.

The wi-fi radio connected with no problem, but I can't seem to get the cell to turn on. (The Mobile Data box IS turned on in the pull down menu.)

Any ideas how I can turn the radio on? I've rebooted several times and toggled the Mobile Data button, but that isn't doing anything. When I tried turning Airplane mode on and off, it hung when trying to turn on.

FYI, I'm running DL30. Other details are:

In device status:
Phone number: Unknown
MIN: Unknown
PRL Version: Not available
ERI version: Not available
MEID: Unknown
Network: Unknown
Signal strength: 0 dBn
Mobile Network Type: Unknown
Service state: Radio off
Roaming: Not roaming
Mobile network state: Disconnected

On About Phone:
Hardware version: Unknown
Model number: SCH-I500
Firmware: 2.2.1
Baseband version: Unknown
Kernel version: 2.6.32.9
Build number: SCH-I500.DL30