Here it is already August and I have received only one postcard this summer. It was sent to me by a European friend who was travelling in Mongolia (as far as I could deduce from the postage stamp) and who simply sent me his greetings and signed his name. The picture in colour on the other side was of a desert broken up by some parched hills without any hint of vegetation or sign of life, the name of the place in characters I could not read. Even receiving such an enigmatic card pleased me immensely. This piece of snail mail, I thought, left at the reception desk of a hotel, dropped in a mailbox, or taken to the local post office, made its unknown and most likely arduous journey by truck, train, camel, donkey – or whatever it was – and finally by plane to where I live.

Until a few years ago, hardly a day would go by in the summer without the mailman bringing a postcard from a vacationing friend or acquaintance. Nowadays, you're bound to get an email enclosing a photograph, or, if your grandchildren are the ones doing the travelling, a brief message telling you that their flight has been delayed or that they have arrived. The terrific thing about postcards was their immense variety. It wasn't just the Eiffel Tower or the Taj Mahal or some other famous tourist attraction you were likely to receive in the mail, but also a card with a picture of a roadside diner in Iowa, the biggest hog at some state fair in the south, or even a funeral parlour touting the professional excellence that their customers have come to expect over a hundred years. Almost every business in this country, from a dog photographer to a fancy resort and spa, had a card. In my experience, people in the habit of sending cards could be divided into those who go for the conventional images of famous places and those who delight in sending images whose bad taste guarantees a shock or a laugh.

I understand that impulse. When you're in Rome, everyone back home expects a postcard of the Coliseum or the ceiling of the Sistine Chapel: send them instead one of a neighbourhood pizzeria with five small tables, three potted plants and the elderly owner and his wife wiping their hands on their aprons and smiling broadly. Fans of quaint and kitschy postcards spend their entire vacations on the lookout for some especially outrageous example to amuse their friends back home, while their spouses consult serious guidebooks and stroll for hours with moist eyes past great paintings and sculptures in some museum.

Once they find the right card, they are faced with the problem of what to write on the other side. A conventional greeting won't do. A few details about the trip and an opinion or two about the country they are visiting are OK, but even better is to come up with something clever, since every postcard is written with a particular person in mind. No doubt, one writes differently to one's friends than to one's parents, who always fear the worst when one is away. Thus it's tempting, when one sits down to send news home, to do the unconventional and use the small space allotted for writing to have a little fun:

"Dear Mom and Dad,

We lost our last penny and maxed our credit cards in Las Vegas and have been hitchhiking ever since, spending a night in jail at times so we could avail ourselves of whatever local cuisine the law enforcement provides in Texas. A priest arrested for drunken driving who shared our cell recently told us that we look like a couple of early Christian martyrs, you'll be happy to hear. The Newlyweds"

Unlike letter writing, there never has been, and there never could be, an anthology of the best of postcard writing, because when people collect postcards, it's usually for reasons other than their literary qualities. If there was such a book, I'm sure it would contain hundreds of anonymous masterpieces of this minimalist art, since, unlike letters, cards require a verbal concision that can rise to high levels of eloquence: brief and heartbreaking glimpses into someone's existence, in addition to countless amusing and well-told anecdotes. Now and then one encounters in antique shops and used book stores boxes full of old postcards valued for their antiquity, their images and their stamps. The writing found on them most often tends to be in faded ink and hard to read. To anyone with plenty of time on their hands, I recommend reading a bunch of them. Postcards continued to be used by people of modest means to convey important family news long after telephones ceased to be a novelty. I once came across one that said:

"Francis Brown died last night, funeral on Tuesday."

That was all there was. The image on the other side of the card was of a famous racehorse from the 1920s, so I immediately pictured Mr Brown with a straw hat, a cane in his gloved hand and carnation in his lapel, stopping for a beer in a saloon before catching the streetcar to go to the track in Boston or San Francisco.

So, dear reader, if you happen, on your daily rounds, to come across in a coffee shop or a restaurant some poor soul sitting alone over a postcard and visibly struggling with what to write, take pity on him or her. They are the last of a species, and are almost certainly middle-aged or elderly, already nervous and worried about all the problems older people face in this country. But this may be a moment of respite for them, as they sit there, happily licking a 29 cent stamp and looking out to see if they can spot a mailbox in the street, to send what may turn out be the last card they will ever write, this one with a picture of your beautiful town or city, with a message that might be interesting or downright embarrassing to read, but most assuredly will be welcomed by its unknown recipient, either in the next state or across many time zones on some other continent and place you and I can't even begin to imagine.