Most conventional fold-out beds present all kinds of potential points of failure, often via complex mechanisms only a professional would be qualified to fix.

This solution is about as simple and non-technical as it gets: two semi-circular couches that come together to make a single guest bed.

Hiding in plain site, The Scoop! by Guido Rosati (for Saba Italia) hides in plain site, configured in whatever pattern fits your ordinary living room layout before it slides to form a well-rounded sleeping platform.