Britons seem almost hell-bent on throwing their valuable electronics away. Thousands of mobile phones, laptops and handheld PCs are left behind in London taxis each year, a survey by Taxi newspaper has revealed.

Absent-minded passengers left a staggering 62,000 mobile phones in the back seats of black cabs in the last six months. Another 2,900 notebook PCs and 1,300 PDAs (personal digital assistants) were left in cabs during the same period.

Jay Cleary, a licensed taxi driver from South London, said that mobile phones were the most common single item left behind by passengers in his cab after umbrellas.

"They usually forget things when they've been drinking or when there's more than one person in the back of the cab," Cleary explained, "They're more interested in talking than collecting their stuff. Also, if they put something on the back shelf of the cab, you can almost guarantee they'll forget it."

Cleary explained that he personally returns most of the mobile phones left in his cab to their owners. "Of course, we charge them for running it back," he added.

Notebook PCs and PDAs, which often contain highly personal information about the owner, can be used for personal gain if discovered by unscrupulous individuals. The findings of the survey add to fears of a rise in identity theft.

Identity theft is a crime in which criminals use personal details to commit fraud, such as unauthorised payments by phone or on the internet. Criminals have also used identity theft as a means to secure loans and commit benefit fraud. Over 750,000 Americans are estimated to be affected by the crime this year, and the problem is growing worldwide.

Stuart Pessok, editor of Taxi newspaper, which published the survey, said the findings showed how careless people can be with valuable personal possessions.

The findings showed that only half of the phones are later claimed by their owners. But the numbers of devices that, having been mislaid, are stolen by other passengers is impossible to estimate.

Magnus Ahlberg, managing director of Pointsec Mobile Technologies, the mobile security company that carried out the survey for Taxi newspaper, said the loss of information stored on electronic devices could put the owner at risk of "exploitation or damage to their personal integrity".

Police in Amsterdam already use a scheme in which they flood phones that have been reported missing with text messages informing users that the handset is stolen. The system is now up for an award for effectiveness, and UK police forces are trying the system out.