I've been using the $5.99 T-Zones plan when not in wifi range... it works pretty well, but one thing I missed was the ability to SSH to a linux machine while on the go.
First I thought I could just set SSHd to listen on port 8080, but that doesn't seem to work from my iPhone to a server at work (I think it has something to do with the proxy redirecting 80 and 8080 already). Then I remembered that POP mail still works on T-Zones without the proxy, so I set SSHd to listen on port 110. Viola!
What I finally ended up doing was just leaving the SSHd config alone and configuring my router to forward port 110 to my server at home on port 22. Now I can SSH in to my linux machine on port 110 from wherever I have EDGE service via T-Zones.
Next step is getting aliases working under vt100 terminal on the phone.
Edit: I guess I should clarify... after making those changes to your router or SSHd server, you can SSH from the vt100 terminal by doing "ssh user@host -p 110". The default port is 22 which doesn't work on T-Zones, so you have to specify the new port 110.
And of course this only gives you access to one specific machine, but from there you should be able to get where you need to go if you wanna SSH to another server that's not set to listen on 110.