there is a write up on how to do this somewhere tho its done with cingular and a razor phone

heres is the skinny tho:

1. make sure you can connect using the phone
2. on the nokia 770 leave the apn blank, the phone no *#99***, the user name WAPS@CINGULARGPRS, Password CINGULAR1

Okay, this is off the top of my head but its something of this nature. you can find the setting off the phone.

ive done it though i havent got the plan and so its cost .o1 a kb. i just did it to see if it works