Geoff J wrote on why prayer works and as the comments progressed I had some thoughts. I started writing on them during a class and now I've got a four part (at present, I may rewrite it) discussion about prayer.
Most prayers I hear appear to be said out of habit or need. Prayers said from habit are like shaking hands or brushing your teeth: part of a routine that has a positive place, but is engaged in because it is engaged in. In times of need, or in times when people think they have a need, they also pray. Everyone has heard the old joke "God, I've never prayed before and if you help me now I'll never bother you again ..."
I've been reflecting on this a good deal recently, because I've slipped into praying just to feel the Spirit and so my children will pray with me and feel the Spirit (too many habitual prayers are empty -- the loss of school prayer is a positive thing in that regard -- one less empty prayer). I haven't had things to talk with God about that I could express, my needs are more than met in my limited understanding of what my needs are, and having the Spirit present has felt like more than enough reason to pray when praying by myself or with my family.
But what about what people think of when they think of prayer? What about praying to God to intercede in the world? What about prayinf for others or for needs? I will write on that next, because we are told that prayer is more than ritual and more than an excuse to find a sense of presence, calm and peace. Not only are we told that it is more, we need for it to be more for us to be fully engaged in living rather than merely existing.