Turn an OS X client into a RAS server?

This is a server realted function question applied to a client OS. I have a cable modem. With it comes no dial up access. I travel frequently and I don't want to have to pay for Juno or anything else. What I would like to do is to be able to dial in to my OS X machine while I'm on the road (I know its long distance but I don't care about that right now) and access the internet. In essense, I'd be my own micro ISP. With all the UNIX goop under the hood there HAS to be a way to do this right? I don't want to remotely control my home Mac, I want to be able to dial in, be assigned an IP, and surf away. Possible?