The Cost of War maintains a counter showing the expenditure on the war in Iraq. As of this afternoon, it had reached $138,693,576,310 and was climbing rapidly (yes, that's 138 billion dollars!). This amount could have been used for any of the following:
a) Completely insuring the health of 83 million children for a year
b) Hiring 2.4 million public school teachers for a year
c) Building 1.2 million additional housing units
d) Fully funding global anti-hunger efforts for 5 years, or global anti-AIDS efforts for 13 years.
e) Ensuring that every child in the world would receive basic immunizations for the next 46 years.
What really makes the site stand out, though, is this wonderful statement by President Eisenhower. He was a Republican, and (having been Supreme Commander of Allied Forces in Europe in World War II, Chief of Staff of the U.S. Army, and Supreme Commander of NATO) knew war first-hand; no-one could accuse him of being a 'bleeding-heart liberal'. He said, on April 16, 1953:
Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed.
Food for thought.
UPDATE: This might help you appreciate how rapidly the costs are increasing; in the time it took me to write this, over 2 million dollars have been spent!