Wow, this took a long time and alot of trial and error to get to work, but finally I got it!

I'm going to post some info in the hope it may help someone else.

My cell phone provider was NOT listed in the mobile operater choices so I picked one (AT & T) and edited it. On the pda, under Preferences/network, I copied the APN. The username and password are there, too, but the password is not readily accesible, if you don't know it you may have to call your provider. I left the dialup number the same as it was and it may just be luck, but that worked.

Once I got all that set up I got a fail to connect message. Luckily, I found this thread that advised turning your treo off and let the 770 wake it. It worked! On mine, if I get a connect sound (sort of a three note thing) then the connection will fail. If it connects silently it works. I do have to turn the BT on and off sometimes to make it work. So, if you don't immediatly get a connection, don't assume it's your settings.