If owning a home is the American dream, knowing what other people's homes look like — and how much they cost — is the prevailing American curiosity. Thanks to the Internet, you can peep into dozens of homes a day, and the owners will never even know you were there. Most of the home-listing sites work the same way. Prospective buyers screen by location, cost, house size and so on. Then you get a list of properties and contact information.

Realtor.com is by far the most extensive site. It claims to have 1.3 million current properties, which is about 90% of the properties on the U.S. market. The site, which is run by NAR, is updated daily. Not all listings provide photos, but they do have detailed features of each property (carpeting in the master bedroom, professional landscaping, vaulted ceilings and so on).

If it's a "virtual tour" you want, check out Homeseekers.com. Within specific listings, shoppers can click on a room they're interested in and watch a 360-degree scan of the entire space. Other sites that display homes, with varying degrees of sophistication, include Homes.com, RealEstate.com and CyberHomes. If you're looking for something less expensive, TowerAuction.com is a directory of mostly low to midprice properties that have been foreclosed. And don't overlook brokers' own sites: Century 21 and Coldwell Banker both have their extensive listings online.

All of these sites can save you a lot of schlepping to homes that are inappropriate, especially if you're looking for a place out of town. Even if the specific listings don't satisfy your requirements, you can get the names of some of the area's most active agents. "Only a few people buy what they see originally," says Sandy Henslin, a Rochester, Minn.-based realtor, who points out that in really tight markets, homes don't always last long enough to be listed online. But at a minimum, Internet home shopping will give you a feel for the marketplace and the name of a broker that sells the type of home you prefer.