I think a lot of people have a misconstrued view of the purpose of prayer/meditation. The purpose is to get oneself in the right mindset to achieve a certain goal. Say I pray to be more kind toward a certain person. God isn't going to instill kindness in me with a spiritual syringe. Rather, I've realized the nature of my actions much change and so I take time to meditate on that.
Prayer is (seems to me) for the one praying, not for the deity. I don't know why more Christians don't see this. If you pray for God to do something he wasn't going to do, surely that's futile.
If you pray for God to do something he was already going to do, surely that's useless. Therefore, if prayer is useful at all, then it is useful for the pray-er, not the pray-ee.