I conducted a test today and to my astonishment it worked! I'm running 10.2.4 on a 12" PowerBook with a SuperDrive. I put a DVD into my PowerBook (I used 2001: A Space Odyssey). Once mounted, I closed DVD Player and opened Disk Copy. I created a Disk Image on the desktop of the DVD (DVD/CD Master, No Encryption). I then ejected the DVD, then double clicked the Disk Image to mount it.
I opened DVD Player and it plays!
So now i have six movies on my FireWire External drive that I can watch anywhere and it seems to use a lot less battery than running them from the DVD disk. I got through 2½ films on one charge!
[robg adds: I haven't tested this, but intend to this weekend - it seems like a great way to travel without having to carry DVD cases around in my travel bag! If someone can verify that it works, please post a comment...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030403161152660