Tourists have long used home swaps as a way to save money and escape the blandness of hotel rooms; trading use of a house on the beach in Florida for a New York City apartment or lakeside cabin for a week or two.

The idea has now spread to permanent swaps. With far more home sellers than buyers in the market today some entrepreneurs have come up with web-based ways of putting sellers together with other sellers in hopes of meeting the needs of both.

According to reports it does work, but visiting some of the sites gives one a new appreciation of the words "needle" and "haystack".

The Wall Street Journal in an article by Jennifer Levitz last month, identified four of these house swap websites and we visited each. If you wish to do the same the URLs are OnlineHouseTrading.com, GoSwap.org, DaytonaHomeTrader.com, and DomuSwap.com. The venerable Craigslist.org is also getting in on the action with 7,392 home swap listings in December, an increase of 56 percent in a year, however, on our quick visit we found that most were still of the vacation variety.

The premise is a simple one. As it says on the DomuSwap website, "there are many more sellers than buyers, and therefore few offers and sales. Many of these sellers, however, are actually buyers needing to sell their existing homes before they can buy." These websites attempt to uncover possible trades thus expanding the seller's market to more potential customers

The smallest of the sites, DaytonaHomeTrader, is operated by a local franchise of Coldwell Banker. Its listings, 24 the day we visited, are limited to Florida and most appear to be from builders who are willing to take on a smaller home, probably as a way to generate activity within existing developments as well as to diversity their portfolios. The house being traded into must have at least a 20 percent greater value than the home being traded and the smaller home cannot suffer from functional obsolescence or deferred maintenance. The site claims 7 success stories since January. There seems to be some rationale to this site as it is geographically limited - Florida sellers looking for each other.

Not so for most of the others. The chance of finding a home in the particular part of Tennessee belonging to a seller who hopes to move to your part of rural Maine seems to be a monumental crapshoot.

As for the sites themselves, we found only GoSwap to be fully transparent and user friendly. A casual visitor can access all listings and get a brief description of the property and find out a bit about where the owner is willing to consider swaps. A simple and free registration allows access to more detail - a comprehensive (or as comprehensive as the owner provides) property description and more information on the terms for a swap. A present there appear to be about 400 listings on the site several of which are in exotic off-shore locations.

GoSwap.org says it is "geared to find a perfect match across multiple property types and eliminate any transaction costs as there are no real estate commissions when owners trade." The site also allows posting ads in various categories and with multiple exchange combinations. One example given in a press release: "what if your kid is going to college out of state and the family is on a tight budget, but you have a piece of land that's been sitting dormant for years? Perhaps you could exchange that property for several years of housing." In fact, we found one owner willing to accept a sailboat in trade for his land in Mexico.

DomuSwap has listings in 48 states and a visitor can view all listings by state and locality without registering. However, you must register a property to trade before you can access information on the types of trades an owner would consider. At the bottom of each site were several categories, each linked to a number - matches, connections, seekers, extended - and some of the numbers were impressive - in the thousands in some cases. But nowhere could we locate an explanation of what the words and numbers meant. Realtors are welcome to post listings on the site and, in fact, are assured that they can keep their commissions, maybe even earn two.

OnlineHouseTrading has received the most press of late but it was certainly the least user-friendly of the sites. You must register to access any of the site's services and indicate in general terms where you are looking and what you have to trade. Once that is done you are presented with a teaser list of possible matches, but with only the price, number of bedrooms and baths. To get any further information you must list your existing property and pay a $19.95 fee for six months (renewals are free.) No browsing at this site.

All of the sites tend, in their promotional materials, to compare themselves and their technology to match-making websites which have certainly been a staggering Internet success. There is also a crying need for some real innovation when it comes to buying and selling real estate. We have to wonder, however, if there is a large enough audience for house swapping and if the concept is practical enough to support even one such site let alone four.