Global, Prayers and meditation

Prayer
Prayer is the act of addressing a god or spirit for the purpose of worship or petition. Specific forms of this may include praise, requesting guidance or assistance, confessing sins, as an act of reparation or an expression of one's thoughts and emotions. The words used in prayer may take the form of intercession, a hymn, incantation, words of gratitude, or a spontaneous utterance in the person's praying words. Praying can be done in public, as a group, or in private.
Most major religions in the world involve prayer in one way or another in their rituals. Although in many cases the act of prayer is ritualized and must be followed through a sometimes strict sequence of actions (even going as far as restricting who may pray), other religions, mainly the Abrahamic religions, teach that prayer can be done spontaneously by anyone at any moment.
Scientific studies regarding the use of prayer have mostly concentrated on its effect on the healing of sick or injured people. The efficacy of petition in prayer for physical healing to a deity has been evaluated in numerous studies, with contradictory results. There has been some criticism of the way the studies were conducted.

Meditation
Meditation is a holistic discipline by which the practitioner attempts to get beyond the reflexive, "thinking" mind into a deeper state of relaxation or awareness. Meditation is a component of many religions, and has been practiced since antiquity. It is also practiced outside religious traditions. Different meditative disciplines encompass a wide range of spiritual and non-spiritual goals; achieving a higher state of consciousness or enlightenment, developing and increasing compassion and lovingkindness, receiving spiritual inspiration or guidance from God, achieving greater focus, creativity or self-awareness, or simply cultivating a more relaxed and peaceful frame of mind.
Eastern meditation techniques have been adapted and increasingly practiced in Western culture. However, in a 1989 document called Aspects of Christian meditation the Catholic Church advised Catholics against mixing Christian meditation with eastern approaches.

Prayer Groups
A prayer group is a group of people that meet to pray together. These groups, formed mostly within Christian congregations but occasionally among Muslim groups as well, gather outside of the congregation's regular worship service to pray for perceived needs, sometimes within the congregation, sometimes within their religious group at large. However, these groups often pray also for the world around them, including people who do not share their beliefs.
Many prayer group meetings are held according to a regular schedule, usually once a week. However, extraordinary events, such as the September 11 attacks or major disasters spawned a number of improvised prayer group meetings. Prayer groups do not need to meet in person, and there are a vast array of single-purpose prayer groups in the world.