a billion dollars well I'd build myself a kickass house in Kenya, and buy an appartment in London, Paris, Venice, Frisco and NY.
I'd get a TV projector in all of them, all of them filled with Uptodate comps and everything that possibly could go over a network would go over a network. Get myself some house staff in Kenya, and some cleaning personal in the appartments. give a certain percentage of my intrests to good causes like green peace, doctors without borders (think it's called that) throw huge parties for my friends.
help out a few african countries and help out the U.N. with money