In what is starting to be a competitive field, Wireless NRG has released a solar-powered iPad case called the KudoCase that offers protection and extra juice for your battery from the sun. The case is made of a hard, biodegradable corn-based plastic and features solar panels on the front cover that generate energy from indoor and outdoor light sources. The solar panels charge the case's built-in battery, which in turn slowly trickles energy to your iPad, topping it off and letting it go up to 10 days before it needs to be recharged (based on two hours of use per day).
Logitech also recently released a solar-powered case that will be sold through Best Buy that is outfitted with a small section of solar panels that power the attached keyboard only. The jury is still out on whether the Logitech case carries any environmental benefit, but it seems unlikely.
The KudoCase on the other hand does help to cut down on the time your iPad is plugged into the wall and like other smart cases automatically puts the tablet to sleep when the case is closed and awakens it when it's opened. The KudoCase can also charge other devices through its USB port and comes with an HDMI cable for hooking your iPad up to a TV or monitor.
To keep track of your iPad, the KudoCase also features a whistle locator that beeps when you whistle so you don't have to search too long when you can't remember where you put it. It's currently only available in black, but will soon come in gray, green, pink and blue for $189.95.