Futons
Futons originated in Asia and were actually just considered to be the mattress that was placed on a floor for sleeping. In western culture a frame is used to support the mattress. This frame converts a love seat or chair into a flat bed.
Futons are great because they save space by combining two pieces of furniture into one. Those who live in small apartments and dorms love futons because they provide seating during the day. Kids also love futons, having a couch or loveseat in a bedroom makes their rooms feel more grown up.
Futons work well with the designs of most rooms. The various combinations of frames and mattress covers give the decorator plenty of options. Some futons are so beautifully designed that a visitor would have a hard time seeing it as anything other than a couch.