The Libretto, an all-touchscreen computer, is the first Windows 7 PC to forgo keys, taking full advantage of the OS’s ability to read multiple points of screen contact at once. Its second seven-inch screen displays a virtual keyboard or can share a double-wide image with the upper screen. It’s sleek and subtle. An accelerometer detects when the notebook is upright, for instance, so you can read side-by-side pages of an e-book as you would a hardbound edition. $1,100.