By Diana Holden

Where the dollar rules

If you wanted to visit or work in another city or country, which would you pick—the one that was the most expensive or the one that was least expensive? Well, given the current state of the global economy, most sensible people these days would probably opt for the place where their money stretched the farthest. That's where Mercer Consulting's 2009 Worldwide Cost of Living survey comes in. The survey, undertaken to provide multinational corporations the information needed to determine the potential cost of paying expatriate employees, is limited to 143 major cities across six continents. A caveat: Some of the places on the list are not normal tourist destinations. Karachi, Pakistan, for example, suffers from a high crime rate so visitors may want to weigh their desire to travel inexpensively against their personal-safety concerns. Others, such as Wellington, New Zealand, on the other hand, enjoy some of the lowest crime rates in the world.

Using New York City as the base city and pegging all prices to the U.S. dollar, the survey measures the comparative cost of over 200 items in each location, including such necessities as the cost of a liter of gasoline, a liter of milk, a fast-food hamburger, and the rent for a two-bedroom luxury apartment. Although the survey is aimed at corporations, it can be a useful resource for cost-conscious travelers as well. The most expensive city on Mercer's list? Tokyo. The least expensive? Johannesburg, South Africa. Where would you rather go?

To find out where the cheapest cities are, read on.