Why is the median net worth of U.S. households so low?

The Federal Reserve's Report on U.S. Family Finances is out. The Big Picture, from whose site I took the pic below, would no doubt argue that it's all Bush's fault for imporverishing people. But even if that is the case, I can't believe that my fellow citizens save so little.











Even the wrinklies aren't doing very well, if we can believe the NYT. Financial assets of only $30,000? Unbelievable!


Update
According to Andrea Hopkins, also apparently citing the Survey of Consumer Finances

Net household worth averaged $448,200 in 2004, up from $421,500 three years earlier. The number looks high because it is skewed by very wealthy households. Median net worth -- the point at which half of the nation's households are richer and half poorer -- rose just 1.5 percent to $93,100.

That's "average" vs. "median" for you.