Converting AC3 to other lossy format Options

[GregDunn]

I have a couple of legally owned DVDs with separate high quality AC3 music-only soundtracks which I'd like to listen to on my iPod. Is there any easy way to tell what the bit rate is on these tracks (just for the heck of it)?

Also, does it make any kind of sense to re-encode in a usable lossy format for listening or should I just bite the bullet and extract them into a lossless format, accepting the size increase? If no one has practical experience with doing this on an AC3 track, I may run some DB tests later - but it won't be for a while.