DR. BEN Robinson, 40, let me into a swanky downtown Denver apartment. I could hear a couple making loud, smoochy noises in the bedroom.

"Nice to meet you," I said. The doctor nodded. The sounds from the bedroom made for an awkward salutation.

"Oh, that's just Steve and his girlfriend," Ben said, smirking.

"Who's Steve?"

"This is his place."

"Oh ... how do you know Steve again?"

"I slept on his couch last night."

And I, via a random Internet exchange, had just discovered a beautiful phenomenon: free hospitality networks.

Ben, a widower expatriate living in Amsterdam, had responded to a Craigslist ride share ad I'd posted in search of someone to accompany me (and share the cost of gas) along my route from New York to California, where I was going for a summer construction gig. The two of us were now about to spend a week together driving from Denver to San Francisco. A veteran of Doctors Without Borders, Ben met Steve through GlobalFreeloaders, an online worldwide directory of people willing to put up strangers in their homes. A few hours after my arrival, the four of us were downing pitchers of beer and talking like long-lost friends.

• • •

"The difference between llamas and horses is like the difference between good and evil," our next host proclaimed. Terry, a retired lawyer, and his wife, Cathy, live on a llama ranch near Durango, Colo., where Ben had set up a weekend-long stay a while back. We arrived at sunset and, before we even entered the house, Terry was insisting we join him in his daily ritual of smacking golf balls across a rolling meadow with the snowcapped San Juan mountains as a backdrop. The rest of the weekend was equally sublime, and I even broke my vegetarian diet to try llama burgers (they tasted like hamburgers).

We pit-stopped in Flagstaff at the Northern Arizona University library to check e-mail. Ben had received a message from, a student at Arizona State with a couch and a floor to share. With little hesitation, we swung south on I-17 toward Phoenix.

Once there, Ben decided to savor a six-pack of Icehouse in the apartment, while Scott and I went to a bluegrass bar. "He's demonstrating that one needs very little money to travel," I offered. "He's right. Neither of us has spent a dime on lodging, and half the money he spends is on a sixer before he goes to bed."

Scott smiled, but seemed to be paying more attention to the door, where two trashy-looking girls were waving at him. He ended up going home with one of them, and Ben and I were headed to California before our host returned.

And that was my first adventure in free hospitality networks. Since then I've stayed with skateboarders in Ashland, Ore., an older couple in Port Angeles, Wash., who loved to bake pies, and, in Bolivia, a man I could have sworn was Andre the Giant's brother – all memorable experiences.

Traveling like this isn't for everyone. It requires tolerance – like, for instance, when you're trying to use a toilet without water in the middle of the night, and your host's schizophrenic mother tries to break in. You have to be flexible, as your hosts might end up canceling on the day of your intended stay, having forgotten it was their best friend's birthday. Of course, you need to keep your mind wide open: You never know when the guy offering you a roof over your head will insist that glaciers occurred after the great flood, when Noah invited all those animals on board his ark. And most important, the online networks that will help you hook up your accommodations work on a reciprocal basis, meaning it's essential that you also host.

Those who are game for any and all of that have a range of trip-planning options – sites like www.globalfreeloaders.com, www.hospitalityclub.org, and www.couchsurfing.com basically all work the same way: You sign up (for free) and provide some (very basic) information, and the sites use the feedback method to try to ensure a safe visit. A July 4 experience convinced me that holidays are a difficult time to reach people, and, generally, the further away you are from your desired destination, the more people are interested in hosting you. (Put it this way: A Berkeley guy wasn't getting too many responses from the folks in Fresno. Had I been a nice girl from Iceland, well, who knows what might have happened.)

In a way, it's astounding that these networks exist. But CouchSurfing founder Casey Fenton sums it up well on the Web site: "I've always wanted a way to get right to the heart of our culture, to seek out knowledge and to locate the most interesting people and situations this world has to offer. I started this project as a way to share that dream. Won't you join me?" So far, more than 15,000 have. Maybe it's your turn.

Trip planner

For accommodation options in the global-freeloading network, check out the following Web sites: www.globalfreeloaders.com, www.hospitalityclub.org, www.couchsurfing.com, www.place2stay.net, and www.travelhoo.com.