The earnest mother read out the whole of the introductory message at the V&A's Power of the Poster exhibition to her squirming offspring: "Through a process of distillation, they can embody complicated messages with a concentration of imagery that has claims to be poetry." Well, that's as maybe, but like the wriggling pipsqueak, I was keen to plunge into this bargain basement of the art world. It was like meeting old friends. The Haagen-Dazs lovers licked their ices under the genial gaze of Force Flakes' Sunny Jim. A pyjama'd mariner kept buoyant by Bovril ("Prevents that sinking feeling") bobbed alongside the Guinness toucan. Benetton's new-born child, still umbilically attached, faced the pregnant man patting his distended pullover ("Would you be more careful...?").

Drawn by the irresistible magnetism of nostalgia, different age groups homed in on the images of their youth. I saw one elderly chap beaming cheerfully at the grieving widow of "Keep Death Off The Roads" (1946). Nearby, the excellent Fougasse series, "Careless Talk Costs Lives", which featured a stylised Adolf popping up as wallpaper in a tea-shop and on bottles in a pub, attracted a circle of silver-haired reminiscers. The exhibition catalogue informs us that the Queen, whom I had never previously thought of as a blabbermouth, vouched for the effectiveness of this droll propaganda: "How carelessly we would have talked during the war, but for Fougasse."

Memories of my own increasingly distant youth were awoken by the psychedelic section. In the late Sixties, I must have spent months hazily staring at "Mr Tambourine Man", Martin Sharp's iconic image of a bubble-haired Bob Dylan. I believe, however, that the exhibition is incorrect to describe the art-work as a "homage". It first appeared in an early issue of Oz, which at that stage had pretensions to being a satirical journal. Since Sharp's design deliberately obscures the "Tambo" bit of "Tambourine", I'm inclined to the view that he was taking the piss.

High over the exhibition hung the balcon formidable of supermodel Eva Herzigova. When this prominent asset was featured in Wonderbra's "Hello Boys" campaign of 1994, it was responsible for several car crashes on the Hammersmith gyratory system. I was interested to see that the Wonderbra also appeared in a 1997 advert for the Victoria and Albert Museum, which cleverly promised an "ELEV&ATING" experience.

But in one respect, the show was inevitably flawed. It is impossible to respond to the majority of posters in the way originally intended. In most cases, we cannot buy the product or attend the event that is being advertised. It would have been great to see The Byrds at the Fillmore Auditorium, but the barely decipherable psychedelic lettering, accurately described as being of an "almost mystic impenetrability", reveals it took place 31 years ago. Even more irksome is the impossibility of seeing the Bonzo Dog Doo Dah Band who, a day-glo poster informs us, were appearing at London's legendary UFO club on 10 February 1967. It is, however, no hardship to have missed the British Empire Exhibition held at Wembley from April to October 1924, advertised by an image of genial workers in a banana plantation. Bertie Wooster's jaundiced view of this event was revealed in the short story The Rummy Affair of Old Biffy: "Millions of people, no doubt, are so constituted that they scream with joy at the spectacle of a stuffed porcupine fish or a glass jar of seeds from Western Australia - but not Bertram." On the other hand, it would have been rewarding to attend the Second Post-Impressionist Exhibition held at the Grafton Galleries in October 1912, with cheque-book in hand, to make an early investment in Cezanne or Matisse. For that matter, I should have quite liked to have seen the Posters exhibition held at the V&A from 23 June to 30 September, 1930. It must be a slight embarrassment to the current administration that the handsome advert for this event promises "Admission Free", while nowadays you are obliged to stump up a fiver.

Even if we never made it to Paris to participate in the evenements, the new pictorial history 1968: Marching in the Streets, by Tariq Ali and Susan Watkins (Bloomsbury, pounds 20), will stir rose-tinted memories in all battered survivors of the Sixties. Admittedly, the shots of students hurling cobblestones on the Boul' Mich' have a certain elan compared with the genial London demo plodding down Fleet Street past the sign of the Olde Cheshire Cheese, but there was something in the air in those days, even in placid old Blighty. I recall joining in an anti-Vietnam demonstration in the leafy streets of Kenilworth, Warwickshire, which must have given the military-industrial complex an anxious moment.

This book does a splendid job in jogging the reader's memory about the unlikely participants in those stirring times. There is arch-revolutionary Eartha Kitt giving what-for to Lady Bird Johnson at a White House Ladies' Lunch: "Many things are burning in this country ... no wonder the kids rebel and take pot."

On the artistic front, we are informed that firebrand radical Richard Attenborough "began filming the anti-militarist classic Oh! What a Lovely War!". We are also reminded that the Grosvenor Square riot prompted that tireless opponent of privilege, Mick Jagger, to write Street Fighting Man and send the lyrics to the infamous underground journal, Black Dwarf. (Can this be the same M Jagger who said in 1992: "My head says vote Labour, but I look at my wallet and vote Tory."?)

But perhaps the most stirring work of soixante-huit was Yoko Ono's unforgettable masterpiece Number 5, a successor to Number 4 (Bottoms). It took three minutes to film but lasted for one-and-a-half hours. "We call it our smile movie because John smiles in it and sometimes says: 'Don't worry, love,' " Yoko explained at the time. "Originally, I wanted to make a movie of everybody in the world smiling, but I just let John represent everybody and send out vibrations. I think people in 500 years' time will watch it and feel the vibrations." Something to look forward to in 2468.

Bearing in mind the decaying eyesight of those who took up the radical cause in the Sixties, perhaps these ageing Trots should be warned about snapping up a glossy mag entitled Revolution. Now in its second year, this dramatically-titled journal has little to do with the violent overthrow of the ruling classes - a fact which becomes apparent when you discover that it is published by Haymarket (prop: Michael Heseltine).

In fact, Revolution is mainly concerned with the commercial exploitation of the Internet. Ironically, in view of its absurd name, the magazine's cover carries a proud boast about its dedication to "plain English". So what exactly are the preoccupations of these Internet incendiaries? The lead item in the current issue reveals the earth-shaking news that "Kimberley-Clark launches transatlantic Huggies site". Over the page, we learn that "Virgin Cola's chat site is a real gas". Gosh! Will anything ever be the same again?