I made a basic cable from here: http://www.jagshouse.com/modem.html . I have this hooked into the Motorola modem hooked up to the PowerBook and the other end into my iMac G3. I use MacComCenter on the PowerBook and ZTerm on the other. It works okm I have the components taped to my desk and it is fine... though I need to find an altoids tin or something to put the parts into.

EDIT: Well It seems that I don't have to have all those parts in between... I just connected with a plain phone cable... This is MUCH better than stargate, I can bring back the memories of Dial-up Internet! I have a nerdgasm every time I hear the sound of a modem connecting...