Come to think of it, have you considered getting those guys to just get MPEG Streamclip so that they can watch the .VOB files without converting them? It'll save you lots of conversion time, and MPEG Streamclip is free. Or, to split the difference, copy them those files to them, and while they watch them, you can convert the files for posterity.
Make sure when you're making the movie files that you have a way of tracking which file came from which DVD, at what format. When you have that much footage, a logical organizational system is essential.
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