I'm becoming more and more convinced, that if God listens to our prayers at all, it is surely not in order to get instructions on what to do next. All kidding aside, and I know someone is thinking "but you do not have because you do not ask..." but does God seriously need our laundry list of requests? If he already knows what we need before we ask, AND he even prays for us on our behalf, when we don't know what to say... then c'mon, really?
I shamelessly ripped off this graphic that I saw the other day, because in most cases, nothing is more true. As sacrilegious as this may sound, I think that Prayer is mostly about changing us. When I cry out that I need God, I'm admitting that I can't do anything about whatever is going on. Sometimes that is true, and other times, we're really just asking God to enable our self pity. If we're just going through the motions, then we'd be better off to get off our ass, and do something about the problem.
The alternative to this is of course, not illustrated in the graphic: There are times when there just isn't anything you or anyone can do. It's interesting that at these times, everybody prays (I'm thinking 9/11, Tsunami/Nuclear Meltdown, personal tragedies). Thomas Carlyle said that Prayer is the deepest most native impulse of the heart of man... and he was an atheist. Prayer is almost like a unique type of soul searching thought/emotion, which one becomes gradually aware, is not entirely secret.
When we pray, do we pray to be heard? Do we pray because it's the only thing we can do? Do we chose to pray, or are we driven to it? Is prayer an activity or an attitude? I've got my ideas.