A nice problem to have...

Billy G. and Melinda need to figure out how to give away $31 billion before it turns into a pumpkin.

Bill Gates's Charity Races to Spend Buffett Billions - New York Times

Although it has long been the largest grant-making foundation in the nation, the Bill and Melinda Gates Foundation is facing an unparalleled challenge: how to give away more money — and do it much faster — than it ever has before.

Largely lost in the June announcement of Warren E. Buffett’s gift of $31 billion to the foundation were its terms. For tax reasons, starting in 2009, the foundation must give away every nickel that Mr. Buffett contributed in the previous year.