According to Newsweek:

$351 billion has been spent or appropriated between 2003 and 2007 [for the war in Iraq], andthe president's additional budget request of $68 billion in 2007 willbring that to $419 billion, if it passes, according to estimates by theCongressional Budget Office (these figures include U.S. militaryexpenditures, expenditures for Iraqi security forces, and spending forforeign aid and diplomatic operations in Iraq). With another $113billion predicted for the 2008 budget, the total direct cost of the warwill by then top half a trillion dollars, $532 billion in all. Thatnaturally does not even begin to take into account indirect costs, fromveterans' care to oil-price rises.