This article from BusinessWeek.com shows how once middle-class communities have morphed into enclaves for the ultra wealthy. It includes a ranking of the 275 richest Zip codes in the country. The winner? Greenwich, Connecticut, which topped the list with a 2006 median sales price of $2,983,000. Five suburban Maryland Zips made the top 275:
#83: Chevy Chase (20815)—$1,043,000
#102: Potomac (20854)—$986,000
#169: Bethesda (20816)—$875,000
#197: Bethesda (20817)—$830,000
#237: Bethesda (20814)—$785,000