Christianity has a long and impressive tradition of meditation. In fact, there are many different forms of meditation that have been practiced within the Christian tradition. A starting point is the conception of private prayer as articulated in the Gospel of Matthew:
But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly. (Matt 6.6)
Private prayer, for Christians, as opposed to the common prayer uttered in church, is a form of meditation, or intense concentration on God, as opposed to on the things of the world.
The monastic tradition emphasized living a life of silent prayer and meditation. There were many meditation handbooks and treatises written by Christian priests, monks, and theologians in the middle ages, such as the "De Contemplatione et eius speciebus" of Hugh of St. Victor. The Spiritual Exercises of Ignatius Loyola (founder of the Jesuit order) remain an important guide to meditation for many Roman Catholics.
Meditation, especially in the Christian sense, is the attempt to become closer to God. It is a way of slowing down the "everyday" thoughts and becoming more intune with the spiritual aspect of your life. Not only is mediation welcomed in many Christian sects, but Reiki healing and yoga is frequently practiced and accepted as well. These types meditative initiatives are a way to provide yourself with "self-care".