Unless you've made a habit of carrying around a solar charger, topping off your phone outdoors can be a bit of a challenge. Well, unless you're living in South Korea. The city of Seoul just announced that it's building a series of outdoor recharging stations along the Cheonggyecheon, a manmade stream in the city's downtown area. The chargers won't draw from the city's power grid, however -- they'll draw current from a collection of hydroelectric turbines embedded in the stream. The project's developer says the stations will be able to fully charge most devices in 2-3 hours. If the five stations currently in production turn out to be a hit, the city says it will consider expanding the network. See? Low battery life is no excuse for avoiding the great outdoors.