LONDON, England (CNN) -- You've just arrived in one of the biggest cities in the world, have traveled for a day by plane to get here and you hardly know a soul. How on Earth do you start to build a life in London?
Enter gumtree.com, an enormous online community that'll help you find a place to live and all the furniture you need to fill it, a job, something to do on the weekend, and even a love life.
If you're a New Zealander, Australian or South African living in the thriving metropolis of London, chances are you're one of the 35,000 people who log on to this Web site every day.
What started as a small online web-based community four years ago is now among the United Kingdom's busiest sites. Its creators claim it has more web traffic than any other UK job site.
Britons and former bond traders Michael Pennington and Simon Crookall -- having moved abroad themselves in the past -- set it up as a way of connecting people who are planning to move, or who have just arrived in the city, and need help getting started with accommodation, employment and social opportunities.
"You get to the other side of the world. It's all going great but after 10 days you wonder what you're doing. Back home, you had an enormous social network. When you move, you've virtually got to start from scratch," says Pennington.
He and Crookall have been surprised by gumtree.com's success. If you've never heard of it, that's because it doesn't advertise itself. The site relies solely on word of mouth, and gets 500 new users each day because of this.
And although it was started with Kiwis, Aussies and South Africans in mind, gumtree.com is now becoming popular with Brits, too.
It doesn't cost anything to place an ad, update or remove it from the Web site, unless you're advertising a situation vacant, which is how the site generates revenue.
What works so effectively now, says Pennington, would have been virtually impossible in the 1990s. Back then, similar information was available from magazines but it was difficult to find a forum where you could offer your own information. "The Internet is perfect for classified ads," he says.
Listings posted on the site's 300 categories range from the ordinary "flat to rent" and "tickets for sale," to the more extraordinary "I'm going on holiday (not sure where yet) with the attitude 'beach, boys and booze'. Email me if you're keen to join," to just plain weird.
For example, take the plea from someone who'll do anything to get his hands on an iPod.
"I desperately need an iPod. It's a long story but if anyone has one they will give me in return for an evening with me (including most sexual favors you can care to think of!) PLEASE get in touch ASAP."
Or, how about the chap willing to swap his girlfriend in exchange for a car.
His posting reads: "Due to recent arguments, wish to swap very fit, blonde, sexy 24-year-old English girlfriend. Will swap for similar Kiwi girlfriend or BMW2002 Tii (round rear windows). Serious offers only thanks"
All postings are checked by one of gumtree.com's six staff members before they go live but Pennington says very few are blocked.
"If there's anything racist, we won't allow it or if a corporate company tries to advertise, we'll stop it from doing so but it's basically a relaxed, open forum," he says.
"We've also got a very racy dating section with postings ranging from 'friends wanted' to 'casual sex'."
He often receives emails of thanks from people who have found a flat, furnished it and even met their partner through the site.
A young South African woman living in London even tracked down her birth father, who lives in New Zealand, through the Desperately Seeking section.
But it's not all good news for users. The site can no longer be downloaded in Romania or Nigeria because of scams originating out of those countries that targeted gumtree.com users. There's also a fraud alert published on the site, warning people about rip-off artists who use gumtree.com.
Pennington believes the gumtree.com phenomenon will only get bigger. There were 72,000 new ads posted during June. That's up from 55,000 in March this year and 25,000 in March 2003.
Similar sites have been launched in South Africa, New Zealand and Australia, after people returning home complained there was nothing similar on offer there. All three are operated out of London.
Pennington says London might be getting bigger, but the Web site brings people together in an otherwise impersonal city and reminds them that it's a small world, after all.