KDirStat (for KDE Directory Statistics) is a small utility program
that sums up disk usage for direcory trees - very much like the
Unix 'du' command. But unlike 'du', it tries to do that in
a structured, comprehensive manner. It tries to provide
the information you are looking for - exactly where all your disk
space has gone when that dreaded 'no space left on device' message
shows up again. Or when your system administrator asks you
to clean up your home directory. Or when you are that system
administrator trying to figure out which one of your users
filled up that supposedly huge disk up to capacity. 

WWW: http://www.suse.de/~sh/kdirstat/

- Andrey Novikov <andrey@novikov.com>