Neat story about Patrick Schlott, an engineer who repurposed old pay phones for people to make calls where cell coverage is poor:

Schlott has taken old pay phones, modified them to make free calls, and set them up in three different towns across the county. He buys the phones secondhand from sites like eBay and Craigslist and restores them in his home workshop.

I’d love to hear more about the technical bits behind this.