Instead of a full VPN, you might want to try port forwarding/tunneling. Some examples: http://www.openssh.com/” class=”bbcode_url”>http://www.openssh.com/ and http://www.stunnel.org/” class=”bbcode_url”>http://www.stunnel.org/
More info and links on SSH: http://en.wikipedia.org/wiki/SSH” class=”bbcode_url”>http://en.wikipedia.org/wiki/SSH
One of would have to open a port through your firewall so the other could set up the tunnel through it.
