Meet juiceBee - the gizmo that tackles the aforementioned problem. Basically, it serves as both a wall charger, providing 2 amps of USB power, and as a rechargeable battery pack that easily fits in a purse or a backpack. In other words, charging your phone or tablet will also recharge the accessory's cell. juiceBee has a capacity of 3000mAh, which should be enough to completely recharge most smartphones at least once. Moreover, it comes with a built-in surge protector, protecting the device being recharged from potentially harmful voltage spikes. And if that's not enough, the device comes with a built-in LED light that serves as a bright flashlight. A juiceBee model for use with a car's lighter port is being planned as well.
But the juiceBee isn't available at your local electronics store, or at least not right now. It is currently just a project that needs to raise additional funding via Kickstarter and it has 19 more days to reach its $50 000 goal. If you like the idea of juiceBee, go check it out. A $49 pledge will get you one of them in October, assuming sufficient funding is collected.