The Logitech K750 Solar Wireless Keyboard has an internal battery, so there’s no need for cords, power bricks, external batteries, or replacing batteries. It does not require actual sunlight to charge, but can use whatever light is on in the room. The best part? It is supposed to work for up to three months without any light on a single charge! I’m guessing that length of time varies depending on how much you type. The USB receiver is tiny, so you don’t have to worry about accidentally breaking it off or knocking it out of the port. It uses 2.4 GHz technology and 128-bit AES, so it is basically just as fast and secure as a regular wired keyboard. The package also includes a wireless extender and cleaning cloth.
List price is $79.99 US, but you can find them for up to $20.00 less with free shipping if you do some shopping around. I’m ordering mine as soon as I finish this post.