OK, so this is what I got, but it doesn't look right...
The set up is as follows:
My Mac is on a wireless network, presumably behind a firewall over which I have no administrator privileges. Further, said wireless network changes my internal IP address randomly at random times, so I do not know what my IP address is.
Note that localhost is a variable IP address.
I forward some port or the other to my DNS:
ssh -R 19999:localhost:22 sourceuser@remotehost
Connect to my remotehost from my machine:
ssh sourceuser@remotehost
And then connect to the port I forwarded:
ssh localhost -p 19999
[solved] Second question, there are a bunch of SSH clients for the iPhone. Which one should I use?
EDIT: Since jailbreak is not illegal, simply frowned upon by the Corporation, I've decided to go with that. I have a nice shell with OpenSSH and the works. Best of all, it's free and it does exactly what you expect.