The folks over at DARPA are at it again, this time trying to figure out if it's possible to build a system that'll take a picture of a soldier standing anywhere on the Earth, from space, and send it to his iPhone in less than 90 minutes. I'll give them this, when they say "think big" they're not kidding. I would imagine the satellites would be straightforward enough. It's the launchers that I figure might be the expensive link in the chain.