maintains a jump-list of directories you actually use
old directories eventually fall off the list
Ported to zsh from http://github.com/rupa/j

INSTALL:
  source into .zshrc
  cd around for a while

USE:
  j [--l] [regex1 ... regexn]
    regex1 ... regexn jump to the most used directory matching all masks
    --l               show the list instead of jumping
                      with no args, returns full list