They are laptop and tablet PC in one: convertible. The device's keyboard and screen can be separated or folded with a flick of the wrist. What was once just a laptop with a full keyboard has quickly become a tablet with a touch screen. The best convertible laptops (2 in 1) thus combine the strengths of both worlds. They are a real work tool and a couchsurfing tablet in one. Devices with flexible form factors are available in a variety of sizes, performances and price classes.