Discovering what's eating my disk space in Linux

With thanks to Wikipedia: -

du (Unix)

$ du --max-depth=1 -c -h -x /

12K /.dbus
17M /sbin
78M /etc
0 /proc
1.1G /tmp
4.6G /home
0 /misc
4.4G /usr
5.2G /var
346M /lib
16K /lost+found
0 /dev
72M /root
4.0K /cgroup
6.5K /mnt
7.3G /opt
4.0K /srv
4.0K /boot
4.0K /media
4.0K /selinux
30M /lib64
0 /sys
9.1M /bin
0 /net
23G /
23G total

Now I can see the villain :-)

*UPDATE* 23/03/2013

On  Mac OS X, the answer is: -

$ du -sh *

2.7G    Desktop
 60G    Documents
 24K    DownloadDirector
2.2G    Downloads
 65M    Dropbox
6.2M    IBMERS
1.8G    Library
  0B    Movies
 25G    Music
5.0G    Pictures
8.0K    Public
  0B    SametimeRooms
4.0K    dlmgr_.pro