Lost property deparments aren’t just for umbrellas anymore. Taxi companies across the world report that mobile phones, PDAs, Pocket PCs and laptops are being mistakenly left in the back seats of taxis by thousands of careless customers.

And it's a global problem. About 900 drivers for cab companies in Chicago, Copenhagen, Helsinki, London, Munich, Oslo, Paris, Stockholm and Sydney reported a deluge of discarded gadgets in their taxis over a recent six-month period.

In Chicago, more than 85,000 phones were found in taxis – about four for every taxi in the Windy City. A little more than half of those were reunited with their owners – in almost all cases by the drivers, says Pointsec Mobile Technologies, which conducted the survey.

While forgotten phones form the base of the mountain of abandoned electronics, 21,000 PDAs and Pocket PCs were also found in Chicago cabs, and about 14,000 of them were eventually returned.

Passengers even left about 4500 notebooks behind. Not surprisingly, these expensive devices were reclaimed at the highest rate – about 80 percent.

Of course, many items get left in cabs. Surveyed drivers reported pets, undergarments, knives and luggage among the mislaid items. London taxi drivers also turned in a harp, a throne, more than £80,000 in diamonds and a baby.

As electronic devices become more sophisticated and improve their capacity to hold large stashes of personal information, having them – and your precious data – fall into strange hands can be scary.

You can do several things to protect yourself against the loss of a mobile device.

First, evaluate how much personal information you keep on your device and how costly it would be if that information fell into the hands of a criminal. If that cost is higher than the cost of the electronic gear, you should consider protecting it. Methods include:

  • Use password protection: If your mobile electronic device contains sensitive information, protect it by using a password or even a fingerprint reader. Keep in mind, however, that your likelihood of retrieving a lost device will diminish if those who find it can't use it to access your contact information.

  • Back up: If you decide to password-protect your device, it’s less likely that the device will be returned. It then becomes vital to make a copy of the information contained on it. That way no one can access your personal information, but you will be able to replace your valuable data.

    And here are some tips for travelling by taxi with electronic gear:

  • Look before you leave: Clearly, the best way to protect yourself from losing a mobile phone or laptop is to make it a habit to check the back seat and the floor every time you exit a taxi. At the same time, it can never hurt to check your pockets, or your purse, to make sure all your devices are there.

  • Get a receipt, every time: A receipt for your fare contains a lot more than just how much you spent. Often, receipts contain the name of the taxi driver and the cab number. If you happen to leave something behind, having a receipt of your transaction will make it much easier to track down your device.

  • Avoid the seat pocket: Don't put your device in the pocket on the back of the front seat or on the seat next to you. Leaving it in a concealed location makes it easier to forget. Also, don't leave items on the top of a taxicab when you are paying your fare.

  • Don't let yourself get distracted: Try to not to talk on the phone while you are exiting a taxicab. If you are preoccupied, you won't remember to check for all your belongings before you leave.

    If you do leave an item, call both the cab company and (if possible) the device itself. Arrange with the driver to have it delivered to you or to your hotel. And don't forget to tip!