The next time you hear someone in government rather casually use a number that includes the word "billion", think about it.  A billion is a difficult number to comprehend.

One advertising agency did a good job of putting that figure into perspective in one of its releases:

A billion seconds ago it was 1959.

A billion minutes ago Jesus was alive.

A billion hours ago our ancestors were living in the Stone Age.

A billion days ago no creature walked the earth on two feet.

And a billion dollars lasts 8 hours and 20 minutes at the rate our government spends it.