If you're a heavy smartphone user, playing golf can be a real drag. If you walk, you're helpless as your phone's battery slowly drains over the course of a round. It's no better in most golf carts as few have ports to plug in a car-adapter style charger.
However, a new product might actually help you charge your phone while you walk the course.
It's called Ampy, and it stores energy using a proprietary linear inductor. Essentially, the product has a magnet that moves along a coil as you move, storing that energy in the device. Then, you can use a USB port to charge any device. The product's developers say one hour of cycling, 30 minutes of jogging or walking 10,000 steps in a day will give you enough juice to add three hours' charge to your smartphone battery. Not bad at all. An accompanying smartphone app will tell you how much energy you've created and calories you've burnt. You can clip the device to your belt, strap it to your arm or put it in your golf bag.
The creators are currently running a Kickstarter campaign. If you contribute now, you can get the device for $75. When it hits the market, it'll be $95.