For some time I have been enrolled in CouchSurfing, the site that allows you to sleep for free in every city in the world, thanks to the creation in 2003 of a travel enthusiast like me. The regulation is simple, you sign up and make available a sofa, or two or whatever you have, consequently you become possible guests.
In every city in the world, be it Barcelona, New York or Berlin, it is possible to request accommodation for sofa friends. Just enter the dates of your stay and choose the possible roommates with whom to share the house.
Il site is sure because everyone can create their own page to present themselves with lots of photos, interests, favorite readings, music and so on and so forth. CouchSurfing allows you to define everything that might or might not bother a possible roommate, such as knowing if the guest smokes, knowing how much can be hosted and what level the host has already reached. Furthermore, you can decide to host only girls or people of the same sex in case of further hesitation.
I levels they go up to the third and you can conquer the highest level with recommendations, reviews from who has already been hosted by that person and the actual number of guests with whom you have already shared the apartment. The site and also the idea is absolutely free, you don't sign up by giving money and you don't expect it, the idea comes from one free and free exchange of accommodation with young people from all over the world.
Io I am already registered, what are you waiting for?