In my apartment, there are two spent AA batteries in the vicinity of my recycling bin. They drive my partner in crime insane. They occasionally make the trip down to the recycling area of my building, but of course there's nowhere to put them. Australia's battery-recycling programs are small at best, although there's now a fledgling service that will pick them up at your business.

But, like, why use batteries if you don't have to? Especially for something like bike lights, which, thanks to LEDs, don't require a lot of juice. And especially given that if you leave the batteries in something like a bike light, they slowly drain even when you're not using it, which is a needless waste. But who's going to bother popping them in and out of the housing before and after every ride?

The dynamo-powered light has three LEDs, which can run in flashing mode for an hour with about a minute of winding.

As a bonus, winding it makes a high pitched whining sound, which is great for annoying people in your office.