I just read Richard Raymond's atheist prayer. Here's mine, verbatim.
Dear God. Kill me. Please! I have lived a full life with no (well, a few small ones, maybe) regrets. I'm ready to terminate my existence. I'm waiting, God. Nothing's happening. I'll try a little harder: please, please, pretty please, oh great God. I know you have the power to kill me; so why don't you? It shouldn't be too hard; after all, I'm 75 years old. You could just give me a heart attack. God, nothing's happening; I'm still sitting here typing. All right. Now I'm down on my knees clasping my hands. I pray thee, Lord, kill me NOW! That didn't work either, so what am I doing here on my knees - feels kinda stupid. Okay, let's try this: nanyah, nanyah, nahhnnnyaah! I dare you! I double dare you. Nothing? Okay, now I'm starting to wonder about you. Maybe you aren't so omnipotent after all - more like IMpotent. You know what, God, I'll bet you don't have any supernatural powers at all if you can't do a simple thing like killing an old man. I'm wondering if you really CAN answer my (and 7 billion other) prayers. In fact, I've come to the conclusion that you don't exist. So there!