I have At+T, 3G service with a samsung sync. I connect via bluetooth and get about 384kbps download with an HSDPA connection. If you don't have 3G/HSDPA in your area you will be on an EDGE connection at about 128kbps. I have the unlimited data connect plan which is $60.00 additional to any phone plan. I also use the Sync to get my laptop on line. I use the USB cable most of the time as the download speed is much better then Bluetooth, about 768kbps. Right now the sync seems to be the best 3G data phone they have. The black jack is nice but I had problems connecting with one when I first got my plan, but they say it's fixed now. The Nokia N75 is a really nice phone, but connects at slower UMTS speed only (384+/-kbps), no HSDPA.

I don't work for AT+T, by the way, I just have researched this alot recently.

BTW. pairing by bluetooth is really easy and the N800 practically connects itself. Also you get some great options for hands free head sets

Good luck!