Rich and Richer (Especially in Greenwich)

Fortune's Almanac of American Wealth seems aimed at a downscale audience. Students, perhaps? Still, it's fun to look through the slide show of wealthy eccentrics and say hi to Hetty Green, meanest billionaire who ever was seen.

Marketers of wealth management services will learn more from Business Week's Guide to Luxury Real Estate.

The rising tide of wealth in the U.S., and the growing concentration of that wealth in relatively few hands, is being reflected in the tiering of the U.S. real estate market. Across the country, there are communities such as Greenwich that were once home to the merely affluent but have been gradually transformed into magnets for the growing class of the super-wealthy. In some of these towns—like Newport Beach in California's sunny Orange County, or Paradise Valley, Ariz.—the golden transformation is recent. Others, like Greenwich and Glen Head, N.Y., have been gilded for years. In each of them, though, the same pattern is occurring: The very rich replace the well-to-do. The very rich, in turn, are displaced by the super-wealthy.

Measured by median home prices, the very ritziest zip code is Greenwich, CT's 06831. Median home value: almost $3 million.

With a population of about 24,000, The Advocate reports, Greenwich has more than 40 bank branches. Plus at least one foreign currency ATM, where the town's many hedge fund managers can withdraw Euros, Pounds, Yen or Mexican Pesos.