In a speech to the Chicago Council on Global Affairs, Barack Obama pledged to double US aid by 2012, if elected President.

For the last twenty years, U.S. foreign aid funding has done little more than keep pace with inflation.  Doubling our foreign assistance spending by 2012 will help meet the challenge laid out by Tony Blair at the 2005 G-8 conference at Gleneagles, and it will help push the rest of the developed world to invest in security and opportunity.  As we have seen recently with large increases in funding for our AIDS programs, we have the capacity to make sure this funding makes a real difference.

John Edwards also made his Global Poverty Proposal recently.

Hillary?

(Via Owen, Steve Radelet also writes about it at the CGD)