An ncurses disk usage analyzer: http://dev.yorhel.nl/ncdu
I find this an extremely handy alternative to du, it's somewhat similar to TreeView on Windows.
$ du -sk * | sort -n | perl -ne '\''($s,$f)=split(m(\t));for (qw(K M G)) {if($s<1024) {printf("%.1f",$s);print "$_\t$f";last};$s=$s/1024}'\''