Auto-add MP3s in a folder to an iTunes playlist

From [Mac OS X Hints](http://www.macosxhints.com/article.php?story=20070301051316596): "If you'd like to automatically get songs from MP3 blogs (to discover new music without pain), and you'd like to automatically add those songs to a pre-defined playlist in iTunes when the download ends (so you have just to fire up iTunes and click Play), well, this tip is the right solution for you."

This is a nifty hack that uses Automator, Growl, and any number of downloading tools to add songs off the internet into iTunes.