I bought a Nokia 770 one day ago but realized that the blackberry 8700c does not support allowing another device to use it to connect to the internet, so...I was wondering if I could purchase an el cheapo Cingular phone that supports their highspeed EDGE connectivity as well as bluetooh and get it on a dataonly plan just to use with the 770 when I travel, caues obviously WIFI isn't going to be available everyone, and even if one carries a range extended, the chances of having service in every part of the US is highly unlikely.

yes you can. cingular data plan is kind of expensive. you might want to try their media net at 20 bucks unlimited but your really not suppose to tether it to the nokia. it might not be a problem so long as you dont use it as your main source of cnnection

The unofficial estimated word from my local Cingular dealer is 3-5 megabytes a day is when they start paying attention to your usage and analyzing whether you're going to lots of HTML pages and your phone only has a WML browser, for example.

That being said, my 770 works quite well both on Cingular's $20/month service, no proxies needed, or T-Mobile's $6/month service, with a proxy and Opera.

Outgoing SSH is blocked by T-Mobile, though you can always run it on different ports on your server.

You can also get pre-paid data with Cingular. If you have a $30/month prepaid plan, you can add a $20/month data plan.