I got one for the Mac now...
MacTheRipper, freeware. The original website has been removed from the web, but is still available at the above VersionTracker website. It can do full DVD unprotection rips, but what I'm using it for is to get individual audio tracks from individual chapters. A bit tedious, but hey, it is free. Right now I have a bunch of .AC3 files, which play in VLC player, so I'll just have to figure out how to move them over to an iPod-useful format, next time I have a moment.