(MONEY Magazine) – Once a ho-hum real estate marketing ploy, the open house has evolved into an American pastime. On Sunday afternoons, you will encounter not only serious buyers but also hordes of "looky loos"--real estate voyeurs who are there simply to check out the decor, sample the chow and assess the value of their own homes. Here's a look at four recent open houses. --PENELOPE WANG

Frenzy! When it comes to lofty real estate prices and jam-packed open houses, few places can top San Francisco. This two-bedroom house in the Sunset neighborhood, on the market for a relatively affordable $649,000, drew 150 visitors and 10 offers--all over the asking price. The winner bid more than $750,000.

Voyeurism! Pam Morton, an assistant prosecutor in Cuyahoga County, Ohio, visits open houses just for kicks--especially expensive homes. "That way," she says, "if I'm ever in a position to afford it, I'll know what I want." At this $659,000 Bainbridge manse, Morton was wowed by the granite countertops and cherry cabinetry.

Spectacle! To attract buyers in a crowded market, realtors often resort to showstopping gimmicks, such as a Hawaiian luau--southern-style--at this $689,000 Atlanta home. As agent Ceci Rogers (right) handed out leis, some 40 visitors nibbled on everything from pineapples and coconut to crawfish to cake.

Serendipity! For years the Graziano sisters, Kathy (left) and Vanessa, have toured open houses together purely as a hobby. But on a recent visit, Vanessa fell for a historic Victorian-style house and decided to buy it. To sell her current home in Denver, she held (naturally) an open house, complete with Irish coffee.