$1,000,000,000,000

Tyler Cowen flags this post by James Hamilton:

A trillion dollars is about the total amount collected in income taxes by the U.S. federal government in fiscal year 2006-- $1.04 trillion, if you're curious to use the exact number. That gives me a simple rule of thumb for personalizing these numbers. If I want to know what an additional trillion dollars in government borrowing or spending will mean for me, I just imagine what it would be like to pay twice as much in federal income taxes for one year.