Greetings,
The DivX converter lets you pick multiple audio tracks to encode with a single video source. E.G., a show with the regular audio and the director’s commentary. I like CloneDVD Mobile better overall, but I do miss the ability to encode multiple audio tracks into the resulting .avi.
(I use a windows smartphone and The Core player and its cool to be able to get effectively twice as much mileage out of a single file.)