I've got an iMac G5 and PowerBook G4 that I use in the dorms at college. I've been using an Airport Express base station the past two years, but I've wondered if it would be possible to share the internet connection without the base station. Does anyone know of a software-based way to share a network connection between to Macs wirelessly without the Airport station? What I'm imaging here is that I could plug the iMac into the network via ethernet, then share the network connection between the iMac and the PowerBook directly via the built-in Airport cards. Any way to do this?