dirspace is a utility which recursively calculates space by directory with output similar to the following:
sh$ dirspace --maxdepth=3 /System/Library
/System/Library/Accessibility,2309418,2meg
/System/Library/Accounts,4335924,4meg
/System/Library/Address Book Plug-Ins,3654925,3meg
/System/Library/Assistant,120670,117kI know, you've already got du -skh, or find and a bunch of pipes - even still.