The wealthiest Americans now have 288 times the net worth of a typical family. Not only that, but the wealth gap between the richest Americans and the typical family more than doubled over the past 50 years.
Here it is in one nice chart, from the Economic Policy Institute via Occupy America | Crooks & Liars:
If you prefer it in words,
The median household saw its net worth drop to $57,000 in 2010, down from $73,000 in 1983. It would have been $119,000 had wealth grown equally across households.
The top 1%, on the other hand, saw their average wealth grow to $16.4 million, up from $9.6 million in 1983.