found this on ripdifferent.com....i guess you can just make two different movies and then put them both on two disks
If you want to edit clips in iMovie, FCP, or QT or something, you'll need to convert them to DV format, which will degrade the picture and audio quality somewhat, but can be edited in QT-based apps. To do so, after ripping with MTR, you can use MPEG Streamclip (free), DVDxDV, or ExportToQT (part of the excellent $10 MPEG2Works suite of tools - requires you to purchase the $20 Apple QuickTime MPEG2 Playback Component). Once you're done editing, use iDVD or DVD Studio Pro to convert them back to DVD format.
Additionally, growch has some further advice on this matter:
As a sidenote for others out there, I was able [to] use [MPEG Streamclip] without having to purchase the $20 QuickTime Component. It played the .VOB (with audio) and was able to spit out a DV version which I'll now be able to import into Final Cut Pro. More importantly I can now take this and other future converted .VOB files and recompress them using QT Pr