I gave up my Palm Treo smart phone last year for an iPhone. It had been my companion for nearly five years, a long time for a cell phone. At the end people laughed at it, and by extension, at me. But I liked the feel of the thing. I liked what it, one of the first smart phones, could do.

Indeed, I carried the chunky thing around for several weeks after it was jilted for the slim replacement that could do so much more for me. But the Treo still sits on my kitchen counter, ready to be used once again, like the Sheriff Woody doll in the “Toy Story” movies, just in case.

Is that love?

It took only a few days after the first Apple iPad was sold in April for videos to appear on YouTube showing people’s first reactions to the tablet computer. A 100-year-old woman took hold of it, leaned over it, peered into it, and immediately began tapping on the on-screen keyboard. A girl — age 2 1/2 — was instantly able to intuit how to play children’s games on it.

Was that evidence of love at first sight? Apple might say so. More than 7.46 million iPads, costing at least $500 each, were sold through the end of September. The rumor websites say Apple has increased production to crank out 3 million of the things every month as it goes on sale around the world. But love? Can you love an electronic device made of glass, silicon and plastic?

Product designers, who think long and hard about chamfering a particular edge so you’d want to hold it, have, surprisingly, not thought enough about it. They haven’t had to, because the idea seemed preposterous. We can love pets, even a toilet-paper-tube chomping gerbil or an iguana that just sits there blinking. People have been known to tear up when selling their house or car. We can develop deep feelings for a grandfather’s gold watch or a well-worn book. Of course, we may fetishize certain things — Louboutin high heels, a Leica camera or a Dualit Combi toaster — if that can be called love.

Love for a device we’d most likely throw away in a couple of years, like a PC, a video player or a cell phone, doesn’t make lot of sense.

But our relationship to electronic devices has changed so radically in the last few years that designers are beginning to think about our attachments to and, yes, love of electronics like smart phones and tablets. More devices are personal. They have become an extension of ourselves — not in the sense an expensive watch says something about who we want to be, but as an actual part of our conscious self.

“It is different now that we carry our second self with us,” says Sherry Turkle, an MIT professor of social studies of science and technology who has long studied the subject of what she calls evocative objects. “We think with the objects we love and we love the objects we think with.”

The electronics industry has moved out of its initial phase: getting something to work. Like watching a dog walk on its hind legs, we initially were amazed not that many of these products do their jobs well, but that they could do it at all. Computers, cell phones, tablets and e-readers do something that no car, shoe or toaster — yet — can do. They can make us smarter. Mobile devices are now able to tell us things we never knew, like the quickest way to get to our destination, where to get a 15 percent discount or where our friends are right now. That it seems like magic — few people anymore understand how electronic devices work — is part of their seductive power, says Turkle: “There is a direct identification with the power of the technology.”

So it should come as little surprise people feel lost or actually grieve when they lose a personal electronic device. “You are leaving your brain behind,” says Mark Rolston, the chief creative officer at Frog Design, a leading product design shop. He says the extension of our brain can be seen in how these products now look and feel. The devices — whether a flat-screen TV, an EVO Android smart phone, a Toshiba laptop or a Samsung Galaxy tablet — have become frames around a screen that gives us access to the amazing software that is that brain. Designers have begun to refer to that screen, in whatever device it is in, as “the window.” The frame keeps getting smaller and the window gets larger and clearer.

In other words, what we’ve become attached to is not the glass and metal and plastic, regardless of how it is beveled, but to the software running on the device. The love wasn’t there until the software got smart enough. “I doubt that people really loved their cell phones,” says Don Norman, a principal of the Nielsen Norman Group, a design firm, and author of “Living With Complexity.” The software inside a smart phone changed that. He thinks people merely like their Amazon Kindle e-readers, but don’t love them because the software doesn’t function as an auxiliary brain.

If you doubt that devotion to the software is really what drives the love of gadgets, consider the religious wars — that’s the best way to describe it — that can erupt online at any moment between Apple and Android devotees, or between Windows and open-source software users. When we change operating systems, we face a wrenching process because we are changing ourselves.

But there is one particular aspect of our affection for electronics that mystifies Norman, who has been in the product design business for more than 40 years. “How can something be lovable if it is replaced every six months?” he asks. “It’s kind of like teenage love.”

So it may not be long before my iPhone joins the Treo on the counter, cast off, but forever in some small way, loved.

© 2010 The New York Times Company