Logitech Bluetooth Multi-Device Keyboard K480 for Computers, Tablets and Smartphones, Black (920-006342)

Multi-device Keyboard: Unique computer keyboard that also works with your Bluetooth tablet and smartphone
Easy switching between devices: Turn a single dial to switch between typing on three wireless Bluetooth devices
Smartphone/tablet cradle: Built-in cradle holds your devices at the ideal angle for typing
Familiar layout: Designed for easy and comfortable typing, including shortcut keys for Windows and Mac

A turn of the Easy-Switch knob allows you to alternate between 3 connected Bluetooth devices.

That's the concept behind Logitech's $50 Bluetooth Multi-Device Keyboard K480, billed as "the first desk keyboard designed for use with up to three devices, regardless of computing platform."

To switch between devices you simply turn the "Easy-Switch" dial to the desired device and start typing. We played around with it and it worked as advertised. It's similar to previous Easy-Switch Logitech keyboards, such as the K760 or K810, but the new K480 includes an integrated slot that holds phones and tablets. The keyboard comes in white or black.