For only the first 6 months of the 2008 budget year the deficit was $311. The budget deficit for 2005 was $318 billion. (12). As of March of 2006, the National Debt was $8.3 trillion. (13) By April 29m, 2008 the debt was $9.33 trillion. That is an additional $180 billion in five months. You can access the present amount of the national debt on a daily basis at http://www.publicdebt.treas.gov/cgi-bin/cgiwrap/~www/opdpnhis.cgi.

By law there is a limit to the amount of debt the federal government can incur. This is commonly referred to as the "Debt Ceiling." As recently as March of 2006 the debt ceiling was increased to $8.96 trillion. That was the fourth increase in the last five years. (14)

"[T]he U.S. economy is mind-bogglingly enormous two and a half times as big as the next largest economy in the world and almost as large as that of the six other members of the Group of Seven combined. The catch is that it has to consume almost incessantly to sustain its great heft." (8).
"Expert analysts at The Concord Coalition, the Committee for Economic Development, and Goldman Sachs project that on our current path budget deficits will total roughly $5 trillion over the next ten years." (15).

On what exactly are we spending all this money? Spending Programs.