Using iptables to direct all port 80 traffic through SSH

I'm currently running Xubuntu on my netbook, and I'd like to get all port 80 traffic running through an SSH tunnel, regardless of whether I set it in the browser or not. Chromium uses your operating system's proxy information, and will not work in linux for whatever reason, thus it is not as easy as setting the socks proxy. I can set up an SSH tunnel for other browsers such as Firefox, but I can't for Chromium. There are other ports I'd like to tunnel as well (pidgin for example), but I won't get into those quite yet. Is there a way to take all port 80 traffic and pre-route it through iptables first, which would then forward it through my SSH tunnel, and onto its destination?