Actually, this page on SourceForge discusses using SSH to traverse a firewall and do a lot of things, including how to web surf the other end and how to use SAMBA on the other end, virtually replacing the need for a VPN. It’s a good article to study applications of SSH and tunneling.
See the following entries in my weblog for past information:
More on tunneling Remote Desktop over SSH
The Hazards of X11 Forwarding
Tunneling remote control
Cygwin vs GotoMyPC et al. -OR- Getting to your machine from elsewhere