Would you put up a total stranger in your home for a few nights -- for free? It sounds a little strange, but hundreds of thousands of people have signed up to do just that -- to surf couches and to have their couches surfed -- on the astoundingly popular travellers' website CouchSurfing.com. CouchSurfing isn't the first such hospitality program: Servas, a network of travelers, hosts and helpers, has been around for 60 years, but the process for being approved is semi-complex (step one: "contact National Secretary in your home country") and takes a month at minimum; most backpackers aren't that organized!

By comparison, CouchSurfing is more like Facebook. People create profiles, and there's a vouching system and an eBay-style ratings/feedback system, allowing those who've surfed your couch to give you positive (or negative) references and, presumably, allay other travelers' fears that you might be a pervy weirdo.

So what do the folks whose couches get surfed get out of it? Usually, the surfers who come through your living room will take you out to dinner or bring you a gift from their home country as a small thank-you, but the real boon -- besides that warm, fuzzy feeling -- is that you can now surf couches, potentially in some of the world's most expensive cities. Want to spend a few days in Tokyo? Hotels average nearly $300 a night, so surfing a couch or two could save you some serious yen. Of course, there are some common-sense precautions that the website recommends you take: single women are discouraged from surfing on the couches of single men (and vice-versa), though some of the couch-surfing backpackers I've talked to have said, with a wink and a nod, that if someone's profile picture is cute enough, they might disregard that rule once in awhile. (Again: not recommended.)

Any way you look at it, travel is getting more expensive: airline fares are rising, and as the economic crisis takes its toll, money in the pocket is getting scarcer. (There are a few new bargain spots as a result of the crisis, however: ever since Iceland's currency took a nose-dive last year, for instance, vacations there have been a great deal.) For a certain segment of the traveling population, anyway, socially-networked couch surfing seems like the wave of the future.

How about you: have any of our readers couchsurfed, or hosted a couchsurfer? How was the experience?