Watch the Using the Tuning Pegs online guitar lesson by Jim Campilongo from Sonic Tele
Another favorite technique is de-tuning by using the tuning pegs. This tends to be a people pleaser and is always a lot of fun to play once you get it down. Remember that in order to get a solid "turn" on the peg that you should try to line the peg up to the 3:00 position when you are tuning your guitar. Also, don't forget to use graphite on the nut to facilitate an easier and smoother turn.