How do you answer the unanswerable questions? How do you respond to the "trivia" or "only God knows" type questions which cannot be answered from the Bible or science (yet)?  This is more of a general question, such as do you blow them off or provide a generic "Only God can truly know the answer to that, and I have faith that he does" type answer?

For example (you don't have to answer these ;) ): 


What was there before God created the universe?
Can God make a rock He can't move?
My general response is to redirect the questioner to what their real issue is - most often, these questions are asked as a way of attacking fringe aspects of Christianity, and the real issue the questioner has is at his heart: he's not yet saved, and is scared that God's not happy with him, so to make himself feel better, he posts strawman and fringe-topic questions to make the Christian he is speaking with look like an idiot.