Think about the last time you saw a phone booth, or any public phone for that matter. It’s probably been a long, Long, LONG time (2006 if our memory serves us right). With smartphones in our pockets, finding a phone booth is like stumbling across an ancient relic. But in London, phone booths have a bit more prestige and tradition. The red phone booth has become an icon of the city, right up there with Big Ben and double-decker buses, but no matter how cute and iconic, they’re not immune to extinction-by-smartphone.

People have been getting creative, trying to find new uses for the retired crimson phone booths we all know and love, to make them relevant so that they don’t end up at a dump somewhere. They’ve been turned into book exchanges, art projects and town bulletin boards. Most recently, they’ve been upgraded to the most innovative, practical function we’ve seen so far — solar-powered mobile chargers.

The Solarbox charging booth is painted green and outfitted with solar panels and charging cords for your smartphone. And guess what? They’re totally free to use! Advertisers pay to have their content run on an iPad that’s in the booth while you’re juicing up. Charging your phone for 12 minutes can get you a 20% boost!

This project was started by two graduates of the London School of Economics as not only a way to repurpose old phone booths, but as a way to use solar energy to save people’s smartphones from low battery.

The flagship Solarbox launched on October 1 in a London shopping area bustling with people, and it’s reported that 85 people used them in one day. It seems like this was a long-awaited update to the novelty, pay-per-call technology. The phone booth’s life is coming full circle, although we will miss that lovely red.

What expired technology would you like to see get updated? Let us know your innovative ideas in the comments!

(h/t PSFK)