There's another pile-up in aisle thirteen

Not the Cromwell Road Sainsbury's
I gather that the supermarket Sainsbury's is trialling shopping trolleys with built-in iPad docks in their Cromwell Road store in London. When I saw the headline, I assumed that there would be some funky Sainsbury's shopping app which meant you could set up a shopping list at home and it would then guide you around the store on the best route to get all the things you need. (Yes, please, Sainsbury's.) But no. Apparently the idea, sponsored by Sky, is that you can watch things like the BBC iPlayer, music videos or, no surprise, Sky's online sports facility.

To add to the fun, the dock is equipped with speakers so you can blast out your favourite tunes or catch all the dialogue in Doctor Who.

Are they serious? Okay, there are going to be lots of fun opportunities for collisions (apparently the trolleys are equipped with sensors on the front to warn you if you are about to collide with another trolley or a pile of tins of beans, something that you only ever see in the movies, sadly). But I'd be more concerned about the noise pollution. Do you really want to walk around a supermarket being blasted by a distorted version of Nero's ecstatic drum and bass in one ear (yes, I is down with the kidz), and a football commentary from the other side of the aisle? No-o-o-o-o!

For that matter I'm surprised Sainsbury's think it is a good thing. Supermarkets are designed to encourage you to spot things you didn't realize you wanted to buy. Huge effort is put into the layout of shops and the order in which you reach things. Bakeries are generally put at the back of the store, for instance, so the smell of fresh bread draws you in. But all this commerical wizardry would be wasted if your shoppers are trundling around zombie-like, watching a screen and missing all your nice displays.

So here's the deal, Sainsbury's. By all means give us a dock and a shopping app. But take away the speakers. Otherwise I'm off to Waitrose.

* Disclaimer - there are other supermarkets, and to be honest I rarely shop at Sainsburys these days, but it's the principle of the thing *