I was visiting New York last week and noticed something I’d never thought I’d say about the city. Yes, nightlife is pretty much dead (and I’m in no way the first to notice that). But daylife — that insane mishmash of yells, chatter, clatter, hustle and chutzpah that makes New York the urban equivalent of methamphetamine — was also a little different. It was quieter.

Manhattan’s downtown is now a Disney-like string of malls, riverside parks and pretty upper-middle-class villages. But there was something else. And as I looked across the throngs on the pavements, I began to see why.

There were little white wires hanging down from their ears, or tucked into pockets, purses or jackets. The eyes were a little vacant. Each was in his or her own musical world, walking to their soundtrack, stars in their own music video, almost oblivious to the world around them. These are the iPod people.

Even without the white wires you can tell who they are. They walk down the street in their own MP3 cocoon, bumping into others, deaf to small social cues, shutting out anyone not in their bubble.

Every now and again some start unconsciously emitting strange tuneless squawks, like a badly tuned radio, and their fingers snap or their arms twitch to some strange soundless rhythm. When others say “Excuse me” there’s no response. “Hi”, ditto. It’s strange to be among so many people and hear so little. Except that each one is hearing so much.

Yes, I might as well own up. I’m one of them. I witnessed the glazed New York looks through my own glazed pupils, my white wires peeping out of my ears. I joined the cult a few years ago: the sect of the little white box worshippers.

Every now and again I go to church — those huge, luminous Apple stores, pews in the rear, the clerics in their monastic uniforms all bustling around or sitting behind the “Genius Bars”, like priests waiting to hear confessions.

Others began, as I did, with a Walkman — and then a kind of clunkier MP3 player. But the sleekness of the iPod won me over. Unlike other models it gave me my entire music collection to rearrange as I saw fit — on the fly, in my pocket.

What was once an occasional musical diversion became a compulsive obsession. Now I have my iTunes in my iMac for my iPod in my iWorld. It’s Narcissus heaven: we’ve finally put the “i” into Me.

And, like all addictive cults, it’s spreading. There are now 22m iPod owners in the United States and Apple is becoming a mass-market company for the first time.

Walk through any airport in the United States these days and you will see person after person gliding through the social ether as if on autopilot. Get on a subway and you’re surrounded by a bunch of Stepford commuters staring into mid-space as if anaesthetised by technology. Don’t ask, don’t tell, don’t overhear, don’t observe. Just tune in and tune out.

It wouldn’t be so worrying if it weren’t part of something even bigger. Americans are beginning to narrow their lives.

You get your news from your favourite blogs, the ones that won’t challenge your view of the world. You tune into a satellite radio service that also aims directly at a small market — for new age fanatics, liberal talk or Christian rock. Television is all cable. Culture is all subculture. Your cell phones can receive e-mail feeds of your favourite blogger’s latest thoughts — seconds after he has posted them — get sports scores for your team or stock quotes of your portfolio.