It's a standard technological wisecrack to extol the bountiful features of a modern phone, pointing out its GPS capabilities, music storage space and teleportation functionality (coming soon, honest) and then saying: "Yes – and it can even make phone calls!" Clichéd, yes, but it's true that the old-fashioned mobile telephone call has become an uninteresting activity for many of us. In comparison to an absorbing 20 minutes playing Angry Birds, it's surely no contest, right? An article on the TechCrunch website last week pointed out the irony that the gadget we carry around with us is referred to as a "phone", when its main use is anything but; it's almost as absurd as referring to an iPod Touch as a radiogram.

At the weekend, I had a rendezvous that needed to be postponed; in a hot-headed moment, I decided to call to rearrange. I figured it would be easier. But it felt strange doing so; the recipient of the call sounded flummoxed, I found myself apologising for calling in the first place, and the call ended in farce when we both realised that our diaries were stored in our respective phones and we'd have to end the call to look at them properly. These days, if someone calls me for "a chat", I adopt the same quizzical expression as if they'd suggested we mud-wrestle each other for kicks. After all, the phone call is an invasive thing – it essentially says, "Listen to me, now!" – and pays no heed to the status of the person you're calling; texts and emails at least allow us to catch our breath and have a think before responding.

While our interest in talking on mobile phones is dwindling – US statistics show the minute count dropping every year since 2007, with average call time half the length of that in 2005 – there are still demographic groups for whom it's still important, and this validates the accusation that anyone heralding the "death of the phone" is probably white, middle class and has a bit of a fixation with Twitter. For example, US statistics show that African-Americans chat on mobiles for 1,300 minutes per month on average, which is double that of white people. Women spend 22 per cent longer talking than men, presumably because we're grumpy and unsociable. But there's one definite indicator of a substantial shift in the way we communicate, and that's the behaviour of under-18s: they spend as little time talking on the phone as 50-year-olds (631 minutes per month) but send a staggering number of texts – 2779 per month, which is more than the rest of us put together. And that doesn't even take into account the millions of instant messages shooting between their BlackBerrys, which are free of charge and slip under the survey's radar.

Some voice communication is shifting to the internet; Apple's FaceTime feature for the iPhone has gone some way to making the video call a slightly less disorienting experience, while Google Voice, the search giant's voice application, has finally been approved by Apple this week to be made available for the iPhone after a 16-month review period. But while these offer a cheaper, easier, more feature-rich way to speak directly to our friends, the signs are that within a generation, we'll all rather opt for sending them a text message instead.

The concept of customer service via social networking is taking an odd turn. Those who make disparaging comments about companies online may occasionally receive a reply from the firm in question, desperate to make amends now that the comment is floating around the internet for the world to see. But for a tweet to have an instant real-life effect is something quite different. A couple of Canadian diners, before a recent visit to a New York restaurant, tweeted that they were eating at Burger King at the airport while en route. When they arrived at the restaurant, the kitchen sent out two mini-lamb burger amuse-bouches, with a note saying, "Hope these are better than the ones you had at the airport." Other examples have surfaced of diners complaining publicly via Twitter while seated in restaurants, the restaurant being alerted, and a waiter quickly offering an apology. Some might deem this passive-aggressive behaviour on the part of the diners, but with all of us having the capability of publishing an instant review to hundreds of people, service industries are right to be on their toes. Although specially prepared amuse-bouches are perhaps a little creepy.