On the island of Malaita, Solomon Islands, I met a carpenter from the small island of Dai, off the north tip of the big island. The little island is home to 300 people. I asked the carpenter if he liked it there, if everybody got along.

“Of course,� he said. “We’re all family. We work together in the gardens and we’re all neighbors.�

They have a few gardens in the center of the island and fish all around it. Nobody goes hungry. A little trail circles the island, and it takes a day to walk it out.

“There’s only one thing we want� the carpenter said, “a cell phone tower.�

“Really?� I asked, thinking of an ugly red and white steel tower rising over the white sand beach and the palm fronds.

He went on to explain. “It’s like this: my uncle and another man took some people from Dai to Malaita. You can see the mountains of Malaita from our island. But Dai is flat, and you can´t see it from Malaita. You have to know where it is to find it. They set out and the sea got rough and they had to fight the waves, going sideways until they ran out of fuel. They drifted on the ocean for two weeks before they were rescued. They were nearly starved to death.�

“Didn’t they catch any fish to eat?�

“They didn’t have any fishing gear, but they were lucky. A few coconuts floated by and they ate those. Otherwise they would have died. That’s why we want the telephone tower, to be able to ring up whenever anyone is in trouble.�

That’s another use for cell phones I hadn’t thought of, sending an SOS from the high seas.

That was in November 2013. Since then I have noticed in places as far apart as Solomon Islands, Uganda, Mali, Bangladesh and Guatemala, rural people are investing in small solar panels, which have been around for some time, but villagers weren’t buying them much. Candles and lanterns provided enough light in villages with no electricity. But now folks are willing to spend money on solar panels, not so much for the lights, but to charge up their cell phones. In the poorest, most isolated villages, most adults have phones, and everybody else wants one. It’s another example of how smallholders eagerly embrace change, when it suits them. Unlike many previous innovations, the cell phone is spreading in the countryside soon after its adoption in the cities. It may speed up the spread of future innovations from now on.