One of the talks here at LCA involved concurrent algorithms for high-speed trading. Which led to the question of how to reduce instability from high-speed trading. Which led to the idea of placing the exchange on Mars, relying on Earth-to-Mars speed-of-light delays to calm things down. Which has substantial scientific benefits: The traders would of course want to place their computers near the exchange, which would put some serious money behind travel to Mars. Which would of course eventually defeat the purpose of placing the exchange on Mars, but life is like that sometimes. Besides, wouldn't it be cool to see a group of rovers chasing each other across Mars, jockeying for the best positioning to reduce speed-of-light delays?