Here's an eye-opening observation from The Economic Policy Institute regarding the distribution of wealth in the United States:
America's 112 million families had combined wealth of $50.3 trillion in 2004. When those families are ranked by the size of their wealth, however, the top 1% alone held $16.8 trillion in wealth, more than a third of the United States' total wealth and more than the $15.3 trillion held by 90% of U.S. families. The top 1% had average wealth of $15 million per family in contrast to the $22,800 average wealth of the least wealthy 50% of families or the $313,500 in wealth for families ranked between 50% and 90%.
The full report, which looks at the possible effects of new tax cuts on the distribution of wealth, is available here.