First and always pull the battery out and reboot it if you haven't already.
If you can get any site to load then it might just be the site otherwise your data connection has been wiped out. You can do a HARD RESET which sets the phone back to factory defaults. I recommend you backup all files (photos music contacts) to a memory card or use your sync cable to a computer.
If you take it to a sprint store they will do the hard reset without asking and you'll lose everything you didn't backup.
Perform the following steps for a hard reset
Pull the battery out. Put the battery back in while holding the RED button down and a reset screen will appear.
Push the up button on the five-way to start the reset process.
Alternate process:
Similar to the hard-reset of the Treo 650. Remove the battery cover.
Press and hold the Red radio button.
Use the stylus to depress the reset button next to the battery.
Push the up button on the five-way when you get a prompt to "Erase all data".
