Tibetan prayer wheels contain mantras written on strips of paper. Spinning the prayer wheel is like saying the mantra repeatedly. Traditional prayer wheels contain hundreds, thousands, even millions of copies of the mantra “Om mani padme hum.” evoking Chenrezig, the Bodhisattva of compassion (Avalokitesvara).
Smaller prayer wheels are turned by hand. Others are powered by water wheels, hot air raising from candles, or the wind. Prayer wheels are spun counterclockwise when looking down on them.
Turning a prayer wheel is like chanting the mantra “Om mani padme hum” (Jewel in the Lotus of the Heart). Reciting this powerful mantra builds positive karma.
An interesting concept is an Internet prayer wheel setup as a memorial to internet pioneer Jon Postel. This web server has a built-in prayer wheel and they even This server “spin” as prayer wheels too. No you know why I scatter the prayer wheel animation throughout JetCityOrange! firstname.lastname@example.org You can build your own.
HHDL says that having “Om mani padme hum” in a file on your hard drive makes it a prayer wheel. To that end you can download this file which has one million iterations of “Om mani padme hum.”
Speaking of digital prayer wheels, the Sakya Monestary here in Seattle claims to make the world’s most powerful prayer wheels. They contain 1.3 trillion (with a “t”) mantras and sutras on a set of DVD’s. This article has background on the Sakya Monesatary prayer wheels as does this piece from Earth Sanctuary. The Nyingma Institute in Berkeley makes more tradional prayer wheels in a modern manner. Others are build prayer wheels full of microfilm
Being a nerd, I make prayer wheels out of empty round Altoids tins.