This clever case uses light to power its built-in Bluetooth keyboard.
Logitech's Solar Keyboard Folio can't power your iPad, but its keyboard can pull in energy from multiple light sources, including the sun and indoor lamps. Once the keyboard is fully charged, you can type on it for two years, Logitech claims--even in complete darkness, assuming you use it two hours a day.
Priced at $130, the Solar Keyboard Folio includes a multi-view stand with two options for typing or viewing. The Folio might not be as rugged as the other cases in this roundup, but it's a good choice for keyboard users who want the convenience of a solar-powered peripheral.