An honor library located inside a converted red telephone box stands on Lewisham Way in London.

A visitor browses books in an honor library inside a converted red telephone box on Lewisham Way, London

A children's literature honor library is inside a converted red telephone box.

Customers line up at the Spier Salads, a converted red telephone box, in Bloomsbury Square, London.

Ben Spier, owner of Spier Salads, at his converted red telephone box in Bloomsbury Square.

Signage advertising items for sale adorn the exterior of the Kape Barako red telephone box coffee stall.

Umar Khalid, co-owner of the Kape Barako red telephone box coffee stall, Hampstead High Street.

Even the most British of icons are constantly evolving. BMW redesigned the Mini; the classic double-decker bus fell out of favor, then came back into fashion; the black London taxi will soon go electric. With the mobile phone effectively wiping out everyday use of public telephone booths, what will become of the beloved scarlet-red kiosks that once dotted the nation?Anything and everything, it seems, from an honor-based lending library to a lunch-salad stand. One is a first-aid stop replete with a defibrillator; another could be the world's smallest art gallery. In perhaps the greatest irony, they seem just the right size to serve as mobile phone repair shops and charging stations.Thousands of the dormant phone booths around the country have been "saved" - re-purposed, mostly as part of nonprofit work. But there's about to be a big expansion in their use as micro locations for businesses.The push to open shops inside the phone booths, or boxes as they're called in Britain, was jump-started by Edward Ottewell and Steve Beeken, who opened the Red Kiosk Company and a related charity. They're refurbished, given a paint job, new electric wiring, specialty glass and locks. The process takes about three months, Ottewell said. "Everything's put back to its original state," he said.Tenants sign leases of three to 10 years that cost about $4,720 (£3,600) a year. After a first coffee and ice-cream shop opened two years ago in the southern coastal town of Brighton, a handful more followed suit around the country.Umar Khalid and his wife run a mini cafe called Kape Barako near Hampstead Heath, London's version of Central Park. Khalid had to scour the internet to find refrigeration, shelving and espresso equipment that would fit inside the box. "It's quite challenging, especially weather-wise," he said. "I do have an umbrella, and I am under the tree, actually, which really helps."Khalid wasn't the only one figuring it out as he went. The shop was closed down by local officials for six weeks while they tried to determine the appropriate license for something that wasn't exactly a retail shop but wasn't a street vendor, either. "It's like a building," he said.After all, he can't just pack up at the end of the day and haul the booth away in a truck. He got his local lawmaker involved and gathered hundreds of signatures of support. He was allowed to re-open, but the question hasn't been settled.The daily fee is about $22 (£17), local Councillor Jonathan Simpson said. "Officers are now working with the kiosk holder to ensure the correct license is issued to allow trading to take place on the street," he said in a prepared statement.Ben Spier is also waiting to figure out what the local council says. He says it will affect his business selling hearty salads out of a booth in the Holborn neighborhood of central London. His menu features a rotation of five salads, plus chicken or salmon. This week his offerings include cumin, paprika eggplant and chickpeas; arugula, pea, mint and parmesan with a lemon dressing; and Scandinavian potato, beetroot, cucumber and pickle.Spier had been selling salads at local food markets for a few years, and the phone box gave him the opportunity to get his own spot without paying prohibitively expensive rent. He built a pod inside the booth and set up shelves that hang from the door. "That was the beginning of May, and it's kind of working out," he said, sounding a bit surprised himself.Two phone boxes in southeast London are run as honor-system libraries, one for adults and the other for children. There are plans for a third, and they're open 24 hours a day.A third of Britain's 46,000 payphones, including about 8,000 red phone booths, are used just once a month or not at all, according to BT, which has operated nearly all payphones in the U.K. since phone services were privatized in the early '80s.Perhaps the most poignant use of the booths - as smartphone repair and charging stations, and mobile office spaces - has the most mass-market potential.New York City-based Bar Works plans to open tiny offices inside the booths, starting with nine in September and expanding to 18 by the end of the year. For about $26 (£20) a month, people will have access to a mini work station with wifi, power outlets, a printer and scanner, and other office utilities.Lovefone, an electronics repair shop, plans to open seven smartphone-repair shops in phone boxes nationwide."I was amazed at how spacious it was and thought it perfect for fitting a single technician inside," Lovefone Chief Executive Officer Rob Kerr said in an email."We already send technicians across the city on bikes performing repairs at home and work with a briefcase of parts and tools, so you don't need a lot of space," he said.© 2016 Bloomberg L.P.