This is a direct rip from A better ls for Mac OS X | hocuspokus, but I thought I'd provide a quick way as a reminder for me on how to get a better ls via MacPorts for OSX.
Download the Snow Leopord MacPorts .dmg from here: http://www.macports.org/install.php
Install it, then run the following from your terminal:
sudo port install coreutils +with_default_names
Boom, now you have an updated ls. Roll on.