Perhaps you should explain what a metropcs is, links, or what it is you're trying to do. Tunneling from a pc over SSH is pretty handy for getting to devices you wouldn't normally have direct access to. For example let's say you do have SSH access to a machine on a remote network. You can create a tunnel over that to get to a different server on the remote network that you otherwise can't get to.

Are you trying to get to something from the NIT or from a pc? It can be done either way. The NIT can act as a client, server, or relay for tunnels over SSH. As a very basic overview you might SSH from the NIT like:
(from xterm)
ssh username@remote.server -L 443:remote.webserver:443
(now from the NIT browser)
https://localhost (or https://localhost:443)

The NIT browser will now see the remote server by pretending that the NIT is the server but actually is a remote server over the SSH tunnel.