This program uses an intuitive interface to help you learn chords. You might imagine that it would be difficult for a program to accurately show you how to play chords, but this one works really well. It can be tweaked for lefties, features an easy-access list of chords (each with alternate options for playing the chord), and shows you where to put your fingers on a virtual guitar fret board. Super Guitar will also play you the chord, so you can tell if you're doing it right. The registration fee is $10.