Inspired by laundr.us.

brandon$ history | awk '{print $2}' | awk 'BEGIN {FS="|"} {print $1}' |  sort | uniq -c | sort -nr | head -10
  78 cd
  76 rake
  61 ls
  60 svn
  24 mongrel_rails
  21 ./script/generate
  19 ruby
  18 ./script/console
  17 rm
  12 ssh