photo from mattermatters.com
While I have been a long time fan of Jasper Morrison's Crate series from Established and Sons, I only today found out they offer a version that doubles as a guest bed. Their Crate No. 5, measuring approximately 79x31", it may suit your smaller guests best, but, as cliche as it sounds, the fundamental simplicity of design and construction imbues the Crate series with both a sense of tradition and innovation. See all Established and Son's products here and, for you new Yorkers, check out Matter in Soho and downtown Brooklyn.