I'm a big fan of trying to be a local when I travel. When I started traveling I would stay at friends' couches (and use the website where people can surf other peoples couches too - apparently Airbnb redacts it if you say the name) , and also hosted a few people in Rio. All experiences were fun and very worthwhile, but now I feel I can give more back than just my joyful presence. ;)
I live with my girlfriend in a 2-bedroom duplex in Copacabana which we sublet when out in vacations. We love to travel and hopefully we can do it more often by using Airbnb.