IMO Prayer could be best described as having communion with God. I don't believe that you constantly have to be talking to Him. I do not even think you have to be on your knees. In fact (personal experience, but I believe many would agree with me), when we get into intense prayer and begin to perceive the presence of God, generally there is a feeling of inadequecy in your words because you realize that He already knows what you have need of. At that point, your part of the conversation will end! You begin to listen to what God has to say and wait for whatever He will impart to you... if He so wills to impart anything at all. You have entered into the presence of God at this point, and you suddenly realize that all you really needed was Him to begin with. It no longer matters if you receive anything from the prayer at all.That is the true point of prayer. Not that we should get what we want from God and go, but that we should come into communion with Him.