Vincent Lai was working at a recycling facility in New York and sorting through a bin of used cellphones a few years ago when he dug up a Palm Treo, a smartphone that was discontinued last decade.

Mr. Lai, 49, tested the Treo and found it still worked. So he took the device home and made it his everyday mobile companion, much as one would adopt an abandoned animal on its way to being euthanized.

“That’s how I think about a lot of my tech stuff: candidates for 11th-hour pet rescue,” said Mr. Lai, adding that he was fired from the recycling facility in 2010 after continuing to take home unwanted gadgets, against the wishes of his boss. Now he works for the Fixers Collective, a social club in New York that repairs aging devices to extend their lives.

Many tech companies are trying to train people to constantly upgrade their gadgets — part ways with a device, the argument goes, as soon as something newer and faster comes along. Companies like Apple, AT&T and T-Mobile USA now offer early upgrade plans that allow consumers to buy a new cellphone every year. Philip W. Schiller, Apple’s senior vice president for worldwide marketing, said at a product event last month that it was “really sad” that more than 600 million computers in use today are more than five years old.