The best thing I saw in London last week was a heap of bananas in Trafalgar Square, masquerading as a work of art.

The artist, Doug Fishbone, had turned up in the dead of night in a big truck with 30,000 bananas and 20 friends to erect the fruit sculpture. And London woke up to find six tonnes of bananas in front of the National Gallery against the stately backdrop of Nelson's Column.

The artist told me that several early morning drunks had walked past rubbing their eyes, probably assuming the mind-altering effect of the drink had not yet worn off.

But a few hours later the sculpture had become impossible to ignore and must have been the most photographed thing in London that day.

Tourists had been told by their guides that some mad artist had dumped a heap of bananas in the famous square and several hundred had come with camcorders to capture the comedy of it all.

People of all ages posed against the bananas for pictures - what would their relatives think of us? And many more were admonished for attempting to eat the art work.

But in spite of all the attention it received, everyone seemed unanimously clueless about what it could possibly mean. The theories were as various as they were wacky. Some thought it was a Marxist comment on capitalist greed, some a marketing ploy and one man in a monkey suit brandished a board calling it 'arto-political-humourism'.

Mr Fishbone refused to talk about its 'original meaning' but his entourage of students admired it for its vivid colour and composition. None of them could define such a 'fluid piece of work' which surely meant that they didn't understand it either.

The artist had earlier announced that at 3pm he would dismantle the installation and hand out the bananas to passers-by. The giveaway caused something of a feeding frenzy as a scrum of tourists, office workers and students dived in for their share. Two Russian women had queued for ages and brought carrier bags, and school kids planned to sell the fruit, hoping its status as art had added to its value.

For a worrying moment the crowd, rounding on the banana heap, seemed at risk of riot and were ordered to stand away and wait their turn.

As the fruit was given out people carrying three bags full scurried off, nervous of being told off for their greed, and tramps smiled as London finally gave them something for nothing. The bananas had brought joy, if not with their aesthetics, then at least for their taste.

As people melted back into the tube station, fruit consumed or hidden away, I suddenly felt a sense of loss as the bright yellow bananas vanished. and the landscape returned, as did the people, to the usual sullen grey.