The Logitech K380  (available on Logitech, $39.99) is a multi-device Bluetooth keyboard that can connect to anything from a Windows PC to an iPhone. The K380 can be connected to any three devices at a given time, and, using three buttons at the top of the keyboard, users can easily switch between any of the three devices. It also has buttons that are not found on all universal keyboards, such as the command button, which is used for Apple computers. With a small, compact design, the K380 is easy to bring anywhere.