This is a switch. Usually the products from Japan's Strapya fall squarely under the category of novelty items, ranging from the to the, er, . But it's finally come up with something practical: a mobile phone strap with a solar charger.
The solar cell can be charged up to 500 times, according to Tokyomango, and can use an AC adapter as a backup battery. It doesn't hold a candle to the, of course, but nothing really can.