Simple Video Capture
Found a very simple piece of software that allows you to capture video on the Mac and costs only $20.
It's called iShowU and it's easy, inexpensive and does what it's supposed to do. You can't take a screenshot of a DVD on the Mac with the built-in screen grabber. I assume this is for copyright protection reasons but in my opinion it's silly because people who want to find workarounds will and I use screen capture constantly to show things, discuss things etc. At any rate, luckily there are lots of great utilities out there and this one does the trick.