[44net] private tunnel?

I am running a gateway using rip, etc. I really only have wifi radio range to a couple other hosts. And that is working well. We have a couple other small wireless networks in town that I can't reach by radio. They could be connected to the internet but unfortunately would be behind firewalls that we cannot control. So till we get things realigned and such, I am looking for examples on how to create a private tunnel from my gateway to those locations. It doesn't really make sense to put another gateway in the portal, as I doubt the rip packets will pass though.