There’s probably no better way of pinching your vacation pennies than sleeping on a friend’s sofa or camping out. But you don’t have to rough it to afford your next getaway.

More travelers are bunking down in nontraditional accommodations, including timeshares, condos and vacation rentals, as I pointed out last year.

The trend seems to be accelerating. The vacation rental industry grew by 17 percent last year, according to the Vacation Rental Management Association. Timeshares sales climbed 6 percent during the same period, says an Ernst & Young study.

By comparison, the hotel industry posted a 7 percent increase in profits in 2007, but is only expected to eke out a 3 percent rise in profits for this year, according to PKF Hospitality Research.

How do you swap out a hotel room for a condo or rental without paying too much or staying on the wrong side of the railroad tracks? After receiving scores of inquiries from readers, I decided to check out some of these lodging alternatives. I also spoke with many travelers who had swapped their hotel key card for a real key.

Here are five tips for making the most of a hotel alternative:

The best deals are online
The Internet is by far the most efficient way to find the right rental. That’s not only been my experience (more on that in a second) but that of other travelers, too. Chuck Cole, a college professor from Thetford, Vt., uses a site called Vacation Rentals By Owner to find vacation homes. “We rented a lovely home in Kauai for a week, and a small house with a wonderful stone-lined Jacuzzi right near the boundary of Joshua Tree National Park, for three nights,” he says. “In places where hotels are very costly, or where you need more than one room, you can save a great deal by doing it this way.” That’s true, but be careful of the information you find on these sites. VRBO has an unusual disclaimer that’s worth reviewing, that basically says it’s not responsible for most of the information on the site. And some of the vacation rental services only allow comments to be posted that the property owner approves. In other words, you may never find out about the vacation home’s shortcomings on the site.

Look for a site with standards
Vacation rentals aren’t cookie-cutter properties that are standardized according to some corporate dictum. But you can hedge your bets. For example, I just rented a duplex in San Diego through a site called Zonder.com. It had a sleek gourmet kitchen, a plasma TV and a rooftop barbecue with a stunning view of Mission Beach. Zonder’s properties are professionally managed, which allows you to avoid some of the problems you might encounter through an open rental site, such as the home not existing at all. That’s what happened to Sue Barnett, an editor from San Francisco, when she tried to rent an apartment in New York through Craigslist recently. “The apartment numbers did not exist, and the phone number we had was no longer accepting incoming calls,” she remembers.

Remember, it’s somebody else’s house
Condos and vacation rentals aren’t sterile hotel buildings with daily maid service. They’re real homes owned by real people. The charming cabin in Lake Arrowhead, Calif., that I recently reserved through HomeAway certainly belonged to someone — a fact I was reminded of when I was asked to sign a multi-page rental agreement and sent a checklist of things to do when I arrived and departed. These rental contracts contain a lot of fine print you won’t find in a hotel, including limits on the number of guests and a “no parties” clause. Which is completely understandable. Wouldn’t you do the same if it were your place? But still, renting someone’s home isn’t for the faint of heart. It’s a lot of responsibility. More responsibility than staying at a hotel.

Since the lodging is nontraditional …
One of the things that surprised me the most when I researched this column was that there’s no one right way to find a vacation rental. Chris Hosford found a lovely rental cottage in Hawaii by running a simple online search for Molokaii rentals. “It wasn’t much more expensive than a nice hotel room and far more pleasant,” remembers the vice president for a car company based in Fountain Valley, Calif. “I had a private pool for my fiancée and I to lounge around, a full kitchen which we used on several occasions, great living room to relax in and was only a short drive to several beautiful beaches.” Other travelers have used a more personal touch. When Karen Kinnane meets someone new while she’s traveling, she invites them to stay in her home when they come to the States. The hospitality is reciprocated. “I’ve stayed twice in a palace in India with complete household staff, and a daily ride on a polo pony, attended all functions of an Indian wedding and a funeral, just like a member of the family,” she told me. “I’ve stayed half a dozen times on a cottage on a multi thousand acre estate outside of Dover, England.” Now that’s my kind of vacation home.

Don’t rule out the alternative
Sometimes the best vacation rental is a hotel. On a recent trip to California, I had the opportunity to experience two vacation rentals followed immediately by a traditional hotel. I thought the first two homes in San Diego and Lake Arrowhead were terrific, and since I had members of the extended family staying with me, it was extremely practical and cost-efficient. But once they all left, we downsized to a room at an Aloft hotel. There were certain advantages to staying at the property, including daily maid service, amenities like a gym and pool, and not having to worry about turning the water off when I checked out. Then again, I had no kitchen to prepare any meals in, so we were forced to sustain our family on deep-dish pizzas from BJ’s Restaurant & Brewhouse and In-N-Out burgers. Still, it’s important to keep an open mind about your accommodations. Sometimes, the tried-and-true is what will work for you.

Finding the perfect vacation rental doesn’t have to be difficult. By conducting a search online and offline, knowing some of the paperwork pitfalls, and keeping an open mind, you can narrow your choices to the perfect property.