A Big Project

Alex Tabarrok at Marginal Revolution asks:

President Bush reputedly asked his big-think guys to come up with a new vision to unify and motivate the nation and they came up with ... a moon base? It's so been there, done that. Going to the moon was one of the greatest accomplishments of mankind but I am not inspired by imitation. Are you?

Hence, I issue this challenge to the blogosphere. What's your big-think idea to unify, motivate and inspire the nation? A moon-base will cost on the order of 200 billion so let's economize and say that the idea should cost 100 billion or less - a better idea and 100 billion to spare! Ideally, the idea should be mostly free of politics and have a strong possibility of success given that the money is spent.

One idea that I've always thought would be really cool would be to drain the world's oceans -- only temporarily, mind you -- so that a bunch of explorers could go see what's really down there. Shipwrecks, geographical formations, Atlantis, a tunnel leading to the earth's core (a la Jules Verne), the creatures from The Abyss, or whatever. Of course the main problem is, what the heck do you do with all that water? My only solution is to build a giant water tank in space, but I'm not sure how feasible that would be.