You've probably never heard of French e-reader maker Bookeen, but their latest product is well worth knowing about: a solar-powered cover for the company's Cybook Ocean e-reader. Its black-and-white design is beautiful (like a medieval woodcut of a leaf),and adding solar power to an e-reader just makes sense. After all, if e-readers have one major disadvantage compared to physical books, it's that physical books don't run out of battery.

A solar-powered cover offers a neat fix to this problem, although we have a feeling the concept may be better than the reality. Bookeen says the device needs an hour of sunlight to charge the 8-inch Cybook Ocean for just 30 minutes, which is hardly a convenient rate. The company also has the nerve to suggest that 30 minutes is enough for a day's reading. As if.) But while there have been similar solar-powered covers for other e-readers, they don't look half as nice. Bookeen's leaf design really is lovely.

The Ocean itself has also only mixed reviews, with sites praising its slim design and large screen, but knocking it for sluggish performance. At any rate, we hope the idea catches on — just imagine a Kindle Paperwhite with built-in solar panels. Bookeen's version costs €59.90 ($67.31), while the Ocean itself goes for €189.90 ($213.40).