The international balancing community is vibrant and growing. Here are links to other artists' sites:
http://www.gravityglue.com - Michael Grab, a very accomplished balancer and photographer.
http://www.crystalbalancestones.com - Beautiful glass crystal balancing stones by glass artist Donna Rice.
http://www.jfceprano.com - John Felice Ceprano. Great work in Ottawa!
http://www.rock-on-rock-on.com - Bill Dan, probably the world's best known rock balance artist.
http://www.responsiblefishinguk.co.uk - Despite its name, this site is about rock balancing.
http://www.stonebalancing.com - Adrian Gray, a well-known balancer in England
http://www.rockpeople.org - Joel Carter, a Minnesota physician, artist, and author.
http://www.dougwestendorp.com/stone-poems.html - Doug Westendorp, who lives in Edina MN (!)
A Brief Tutorial
Balancing rocks is a learned skill. Most anyone can learn it with a little practice. This brief lesson could get you started on a lifelong passion!
It's tempting to grab a few rocks and try to go three or four high right away, but expecting too much too soon is a sure way to frustration. It may be possible for a novice to get some rocks stacked up, but they will likely look flat and not very dramatic. It's much better to start with one rock, learning to balance it with some panache before trying two or more.
Choose a longish rock with rounded ends, and try to balance it on a boulder or other stable base rock. Find a depression, chip, or bubble in the base, not too small -- at this point try for something not much smaller than a half-inch wide, and deep enough so that your balancing rock does not "bottom out" in it. Nestle a rounded end into the depression with the rock roughly vertical.
Feel the direction in which it is trying to fall. Turn and twist, "walking" it around in the depression, always gently tilting opposite the direction it wants to fall while trying to keep the end nestled in. You will eventually feel certain positions in which the tendency to fall is less pronounced. Pursue these as you continue finer adjustments. Eventually your fingers will sense a point where the rock attains stability: As you loosen your hold on the rock, it will no longer be trying to fall over, but will almost imperceptibly seek to maintain its vertical orientation. Loosen your hold further, making any necessary final adjustments by feel, until you have let it go altogether. With luck, you can take a step back, shake the ache out of your arms, and admire your first balanced rock.
Stay with one rock until you have mastered it, balancing it again and again, trying a different contact on the base, the other end of the rock, a different rock. Practice using a contact that is on a slope. Try a smaller contact. Choose a depression contact on the underside of the rock you're balancing coupled with a smooth surface on the base rock.
Adding a second rock complicates things. If you can find a suitable contact on the second rock directly above the first rock's balance point, all you have to worry about is trying not to disturb the first rock as you place the second. If you can't, then you have to adjust the first rock to account for the shift in the center of gravity you caused by adding the second rock. It all gets easier with practice, but it pays to take one step at a time.
The technique described above is just one of many. You can also try stacking flat rocks to great heights, building cairns of rocks in a shape that has meaning for you, or building inuksuks, those human-like sculptures featured in the 2010 Winter Olympics. Rock balancing is a great way to unleash your creativity.