I have a 100gb HD on my MBP and can never seem to free up more than 30gigs at a time! Well now I see why!! I have Final Cut Express installed, which came with LiveType (Which I never use anymore)....well that's takin up 10gigs. My ACR cache was takin up 5 gigs. Whole host of other things I didn't think to look at but this program showed me exactly.
So if you're like me and you're trying to free up HD space and can't figure out what to delete....try this program!!
It has a shareware version that will only measure 20gb but the full version is only $12.99. Not bad considering how helpful it is!
Anyway, just thought I would share!