Ever get the feeling that a cab driver is taking you the roundabout way to your destination in order to bump up the fare? Actually, this has happened to me a couple of times over the 12 years I’ve been traveling as a journalist. In one instance, I called the driver on it and he first played dumb about getting lost. He then came clean and told me passengers should pretend they’re from that city so other drivers will be less likely to take advantage of naive visitors.

But the Web can help you out, too. You can find out how much the cab fare should be before you even step into the car by using a tool on a site called WorldTaximeter, available for free on your PC or mobile phone.

This clever "mash-up" site combines directions from Google Maps with local cab fares to give you an estimate of the cost of a cab ride in cities worldwide. Currently, the site offers support for New York City, Paris, San Francisco, London, Toronto, Rome, Barcelona, Madrid and Prague, with many more cities in the works. Each city listing also provides two or more local cab numbers to call.

The site claims to have more than 85 percent accuracy, and growing.