Hamburg  - The idea is as simple as it is ingenious - people from all over the world come together in an online network to offer accommodation on their sofas to others. In return, they can spend time abroad on a couch anywhere around the globe.

Online communities that bring so-called couch surfers together such as hospitalityclub. org, bewelcome. org and couchsurfing. com are booming.

Couchsurfing. com alone has about 600,000 members according to the website's operators. But in order for you to enjoy a good night's sleep on a foreign couch, there are a few things to take into consideration.

The first issue to deal with is the sheer number of people looking for low cost accommodation.

Big cities are popular destinations and the people who offer their couches like to select their guests

The people at couchsurfing. com advise their clients to search for a host with similar interests.

To find the right host, read their profile carefully and present a positive image of yourself when you contact them. If you can find common interests when communicating by email with a potential host, you improve your chances of being chosen.

Human relations should be your prime concern when looking for a low cost place to stay abroad.

"Of course I'm saving money," says Manoella from Hamburg, "but it is mainly about meeting interesting people."

Manoella is originally from Brazil and at the moment does not have a place to offer, so in the meantime she is guiding couch surfers around Hamburg.

Visitors are grateful for a tour by a local person, according to Michael, 36, from Dresden in eastern Germany.

The most important thing about couch surfing is that you get to meet people who you would normally never talk to and you get an insider's view of the city you are visiting, he believes. Michael has provided about 30 couch surfers with a place to stay and has been to destinations in Eastern Europe about 10 times.

"I can say that I know couch surfing from both perspectives."

Robert is in a similar position. The Berlin dweller spent a total of 20 nights with couch surfing hosts during a trip around Europe and hosts between two and four people a month. But what's it like to have a stranger in your home?

"The host always sets the rules," says Michael, and the host decides whether smoking is permitted in the apartment, when guests should be back home, whether they get their own key or if they may use the telephone.

Otherwise, not much else is discussed in advance, explains Robert.

"The guests gets my mobile phone number, the address and the name of the underground station where I pick them up."

After the first meeting, talk quickly turns to a sightseeing programme.

"The guest tells me what they have been planning and I supply them with tips and information about Berlin - including a map of the city," he says.

Robert says there are no hard rules at home. "In general the same rules apply that apply everywhere else."

Those rules include one whereby the guest brings a present for the host.

"I bring coffee from my home country," says Manoella. Michael usually brings a CD with music he has burned at home.

Another aspect to think of as a couch surfer is food and drink.

"When I arrive I put something in the fridge," says Robert.

That makes sense as couch surfer and host often dine or go out for a drink together.

"There is a rule that says the guest must pay for drinks," explains Michael.

The operators of couchsurfing. com also advise guests to occasionally do the washing up and not to leave anything lying about. (dpa)