Then wait to see the cashier's face when she scans the can and finds out the price is $530 billion.

I told him this would not work at my supermarket. Prices are marked up so high that $530 billion for a can of beans sounds about right.

In Britain, in summer, I went to one of those new do-it-yourself supermarkets where customers themselves use the barcode scanner to zap their purchases. I zapped my hairy left forearm and the machine could not give me a price, but it seemed to think my arm was made by Kellogg's.

I had a sudden urge to take the scanning gun to the zoo to zap the zebras and tigers, which must surely cost a fortune. Zoos are on my mind after a reader sent me a news report about one in China which is struggling with an infestation of dancing grannies.

Since time immemorial, old folk in China have gathered to do elegant tai chi movements to the sound of birdsong. But these days, scary, intimidating gangs of older women do line dances to boomboxes playing music so bad elevators would hang their heads in shame. I once got up early in Shanghai and found a mixed group of octogenarians doing the lambada in the dark outside my hotel. It was one of the most disturbing things I'd ever seen.

The report said that dancing grannies banned from residential areas in Nanjing city have colonized Hongshan Zoo - and are traumatizing the giant pandas and giraffes. Considering how terrifying normal zoo-goers are in China, that's got to be bad.

Why are these elderly ladies exercising so militantly? I think they're planning a global takeover. This would be good. If grannies ran the world, wars would be replaced by chicken soup contests.

There'd be no traffic accidents since everyone would have to drive at 20 km an hour with their left indicator on. And there would be no disorderly conduct on the streets, since we'd all be too embarrassed to step out of our homes in our shapeless, hand-knitted jumpers.

But mostly, the world would be filled with love, because everyone loves grannies, with the exception of officials at Hongshan Zoo, who told police: "Visitors are complaining, because when the dancers start up, the animals go back inside their cages and refuse to come out.

"Random thought: if you can read zebras with a barcode scanner, can you read leopards with a QR (spotty barcode) reader? I would check for you, but unfortunately it's hard to "borrow" a scanning gun from a scan-it-yourself supermarket because there are security sensors everywhere. This could be problematic for people like me who scan their own body parts for fun. "But sir, I did not pay for these hairy legs because I brought them into the supermarket myself, honest. Even if the machine does say they are made by Kellogg's."

Nury Vittachi is an Asia-based frequent traveller.