These commands enable the Wheezy repo for firmware releases of 1.6.0 and later (which are based on Debian Wheezy, rather then Squeeze):

  set system package repository wheezy components 'main contrib non-free'
  set system package repository wheezy distribution wheezy
  set system package repository wheezy password ''
  set system package repository wheezy url 'http://ftp.us.debian.org/debian/'
  set system package repository wheezy username ''
  set system package repository wheezy-updates components 'main contrib non-free'
  set system package repository wheezy-updates distribution wheezy/updates
  set system package repository wheezy-updates password ''
  set system package repository wheezy-updates url 'http://security.debian.org/'
  set system package repository wheezy-updates username ''

You can then do:

  sudo apt-get update
  sudo apt-get install <package>

And install useful packages like 'nano', 'iftop', or 'tshark'.