What would you do with $700 Billion?
nazgulnarsil: money doesn't solve problems, smart people do.  money is just a way of freeing smart people of distractions.
and i think 70 billion in todays dollars is a lot more realistic than 700 billion.
that said:10 billion for space elevator research10 billion for terraforming mars research10 billion in scholarships available to anyone in the world as well as the money needed to pull strings to get the smartest kids into the best colleges.10 billion for a clean water research30 billion in free contraception/medical for every country.