Planet gnome have started a trend...

$ history | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' | sort -rn | head
114 ping
107 sudo
82 ssh
71 top
71 cd
68 iwconfig
56 ls
46 usbkey.sh
43 ps
33 evolution

The output shows what commands you type ...