I'm predominately a PC user, but I still have an old Mac Cube I use at home to listen to internet radio. While searching for an easy way to transfer some of my favorite DVD's to my new iPod Video, I came across this powerful free software that would allow you to rip a DVD directly into the QuickTime mp4 format needed to play the movie on an iPod.
This video format is also known as H.264 - It allows for very small file size and great image quality.
The software is called "Handbrake" and it only runs on a Mac. I've never use software that was so easy to use. Literally one click to rip the DVD to iPod Video. Handbrake can be found at: http://handbrake.m0k.org/
On my old Mac Cube it took about 4 hours to rip the DVD (Batman Beyond). The resulting file was about 680 MB. The image quality is great and it only takes a couple minutes to transfer it to my iPod via iTunes.