Christian Meditation and the Jesus Prayer

"The Jesus Prayer" is an ancient prayer used by many Christians for meditation. the prayer itself is simple: "Lord Jesus Christ, Son of God, have mercy on me, a sinner." One practice is to repeat part of the prayer while breathing in, and part while breathing out over and over. More information can be found at:
http://en.wikipedia.org/wiki/Jesus_prayer
and
http://www.goarch.org/en/ourfaith/articles/article7104.asp.