Planning a long weekend in New York or a week in Paris, but don’t want to blow your budget on accommodations?

Airbnb.com, a 2-year-old Web site, pairs travellers who need a place to stay with people around the world with one to offer. It’s a cross between crashing on a stranger’s sofa and staying at a hotel -- and can be cheap and congenial.

Through Airbnb, you can rent a person’s couch, a bedroom in their home or their entire house or apartment -- choosing from more than 12,000 listings in 2,700 cities worldwide.

For $160 a night, for example, you can get a giant boot-shaped cottage in New Zealand, with breakfast delivered daily to your front door.

In the Montmartre neighborhood of Paris there’s a top-floor apartment with a 180-degree view of Paris for $73 a night. On Seattle’s Capitol Hill, you can crash on a pull-out sofa for $35 a night with a retired racing greyhound named Margo as your co-host.

For travellers who crave the unusual, the Web site’s more eclectic rentals include treehouses, lighthouses, castles and even a teepee.

Airbnb uses an open, eBay-style platform that allows anyone with an available place to list it for rent (along with photos of the rental) after they’ve completed an personal online profile. The profile includes the host’s name and occupation and may also include a personal photograph. Travellers can search by city or country, and filter by price and room type.

I stumbled across Airbnb by accident when a friend and I were searching for last-minute accommodations for a weekend trip to Vancouver during the Winter Olympics in February.

The studio we found in the Yaletown area included free underground parking and Internet access and was just a few blocks from the BC Place stadium and other downtown Olympic venues. The nightly rate: $94.

I immediately was skeptical since similar rentals in Vancouver were going for four or five times that rate during the Olympics.

Once I discovered the Vancouver condo, I e-mailed the host via the Airbnb site -- the only way you can make initial contact. James, the condo owner, didn’t have a photo of himself on his profile and no previous user had reviewed or recommended his property, adding to my initial skepticism. But he responded promptly to all my questions.

We confirmed the dates for the rental, and I reserved using my credit card (PayPal also can be used).

Airbnb warns hosts and guests against making off-system payment arrangements. For one thing, that cuts Airbnb out of the financial deal -- the company makes money by taking up to 12 percent of paid reservations and a flat 3 percent fee is charged to hosts for processing -- but the Web site operators say it’s also a way for users to avoid getting burned.

Airbnb collects the total amount of the reservation at the time of the booking as a signal to the host that the traveller is serious. And as a sort of insurance to renters, it withholds payments to the host for up to 24 hours after the person arrives.

"If there’s a problem we hear about it quickly," said Nathan Blecharczyk, an Airbnb co-founder.

Airbnb screens neither host nor traveller, though the sites does provide some common-sense tips about how each can protect against scams. Many hosts charge a refundable security deposit; some charge a nonrefundable cleaning fee. Those transactions currently are handled strictly between traveler and host.

"These are total strangers," Blecharczyk said. "It’s why we stress transparency. We have a platform where people are expected to have a profile, upload pictures. We don’t verify that information."

We found the Vancouver studio to be just as the host had promised -- modest, clean, comfortable and fully furnished -- perfect for a weekend stay.

The owners were a wonderful couple who said they had maintained the same rate on the condo during the Olympics. They supplied free shampoo and soap, a hair dryer, clean linens and towels and even stopped by later the first evening and left a care package hanging on the door.

The Web site was started about two years ago by three San Francisco friends -- guys in their 20s who saw an opportunity to make a few bucks to pay that month’s rent.

A popular convention had snagged all the available hotel rooms in the city and two of three who were roommates at the time decided to rent out an airbed in their apartment.

"The results broke all our assumptions," said Brian Chesky, one of the founders. "We thought we’d get all guys. We got a 35-year-old woman from Boston, a 45-year-old father from Utah and a design engineer from India."

They launched Airbedandbreakfast to cater to convention-goers -- "fulfilling the needs of travellers when hotels are sold out," Blecharczyk said. It gained momentum after the Democratic National Convention in Denver in 2008, linking conventiongoers to those willing to give up their home for that time.

The Web site -- now www.airbnb.com -- evolved to cover regular travel when the three friends realized they didn’t need a convention to bring people together.

"It turned out there were a lot of people out there looking for places to stay where the hospitality was genuine and the M&M’s didn’t cost $6," says the Web site. But the Airbnb name -- derived from their airbed rental -- stuck.

The Web site has listings in 119 countries -- and about 140 listings around Seattle.

Shireen, a 37-year-old Seattle woman who uses the site to rent out the couch in her Capitol Hill apartment, said it’s a way for her to make a few bucks.

She said she uses a few screening tools, such as verifying the background of everyone who requests a reservation.

Still, she’s not told her parents what she’s doing. "I’m fairly confident they wouldn’t approve; they wouldn’t think it’s safe," she said.

In the last year, she’s rented to about seven people -- men and women of all ages travelling alone -- some of whom she said she’d visit if she’s in their hometowns. Neither she nor her greyhound, Margot, has had a problem with any guests.