A simple python script to clean up the /var/cache/pacman/pkg directory.  More versatile than pacman -Sc in that you can select how many old versions to keep.

Usage: cache_clean {-p} {-v} <# of copies to keep>

# of copies to keep - (required) how many generations of each package.
-p - (optional) preview what would be deleted.
-v - (optional) show deleted packages.