Here are a couple of links that look at this quesion.
Ponds and Streams: Wealth and Income in the U.S., 1989 to 2007 by Arthur B. Kennickell of the Federal Reserve.
Go to page 34, Table 3. The gini coefficient for net worth went from .7863 in 1989 to .8120 in 2007. As the gini coefficient gets closer to 1, the distribution gets less equal (the gini coefficient can go from 0 to 1).
This link from the Cato Institute shows different estimates of what the top 1% owns. The EPI actually shows the top 1% owning less of the wealth in 2007 than it did in 1989 or 1998.
Here is some related information.
Click here to see the data
At this link you can see the gini calculated after taxes and transfers and, it seems, is adjusted for household size. For all people in the mid 2000s, the US has .38 and the OECD average is .31.
Here are the mid-2000s Ginis for household income in selected countries After taxes and transfers and accounting for household size. The U.S. is not that much different.
OECD Total 0.31
United Kingdom 0.34
United States 0.38