Quoting from The Daily Reckoning:
Well, let's see; the current total debt of the United States alone, as measured by the National Debt, is almost $9 trillion. And how much gold is in the Treasury? For that, we turn to The Financial Management Service of the Department of the Treasury, which came out with their "Status Report of U.S. Treasury-Owned Gold" dated March 31, 2007. It reports that the Fed has 261,498,899.316 Fine Troy Ounces of gold, which they value at $11,041,058,821.09. This comes to about $42 an ounce, an artificial government fiat value that hasn't changed since the '30s when gold WAS $42 an ounce.
At $660 an ounce, on the other hand, that seeming treasure trove of 261 million ounces of gold has a current market value of a mere $172.6 billion, which is chump change anymore. I mean, it's less than the deficit in the annual federal budget alone!
So, using Mr. Sinclair's formula, I grab my calculator, punch in the figures for $9 trillion in debt backed by only 261 million ounces of gold and, after a lot of data-entry errors, a lot of cursing and throwing the damned things across the room a few times in frustration, I find that gold would have to be worth $34,500 an ounce, right now!