An idea that was spurred from my urban employment class today: Imagine President Obama, in 2009, pulling all forces from Iraq, then submitting an "emergency appropriations bill" for American cities for the same amount that we spend on war.
$90 billion in one year to build schools and transportation networks in the entire US? If all school districts in the US spent $22 billion on school construction in 2005, then you could double nationwide school construction, with $68 billion left over for spending on roads, transit, port security, and ponies.
Call it a dividend for peace. This kind of investment by a new president would do for the America of the 21st century what Eisenhower did for the US of the 1950s.