Creating Harmonics by Guy Fenocchi is a free video guitar lesson on playing a chiming bell type sound called harmonics. Harmonics are produced by dividing the string in sections and lightly touching the string with our left hand directly over the fret and then plucking the string with our right hand. We'll learn to play harmonics at the 12th fret which is the half way point between the nut and the bridge.
Watch the lesson: Quicktime or Flash

Tuning Methods by Guy Fenocchi is a downloadable Quicktime video lesson that will teach you three different ways to tune a guitar to itself. You will learn how to tune your guitar using unisons, octaves, and harmonics. Many people know the unison technique but learning how to use octaves will help open position chords sound more in tune. Tuning with harmonics allows you to take your hands off the guitar and thus makes it easier to move the tuning pegs. $4.99
Watch sample clips: Quicktime or Flash