Hail one of the cute antique convertible taxis buzzing around the old city, and the driver -- a lovely young woman with a ponytail that whips in the wind, if you're lucky -- will zoom along the shorefront at 50 miles an hour.

On your left, Old Havana continues to decay elegantly. On your right, young Habaneros hang out on the seawall seeing and being seen. Faster than you can say "Guantanamera," you're pulling into the elegant Hotel Nacional with a screech of tires and a flourish. All for about $5 -- if you're a good negotiator. (Of course, American citizens shouldn't forget that the Cuban experience technically requires the blessing of the U.S. government.)

The ride from Hong Kong International Airport at Chep Lok Kok to Central Hong Kong is a marvel of civil engineering. Leaving the massive terminal, you soon find yourself racing over Kap Shui Mun Bridge on your way to the very impressive Tsing Ma Suspension Bridge -- at 4,500 feet, one of the longest bridges in the world and the longest auto/rail crossing.

Way down below you'll see lots of ship traffic navigating the fast-moving currents of the channel. Next comes the smaller Ting Kau Bridge, which links to the mainland, and from there it's a not-so-scenic trip across Kowloon and through one of the three cross-harbor tunnels to Central Hong Kong. Quite an eyeful for about $45.

A straight shot down 5th Avenue in the back of a yellow cab with an aggressive driver can feel like an amusement park ride (albeit one where English may not be the primary language spoken, but thanks to the city's grid system, that's usually not a problem). By day, he'll weave in and out of traffic while you watch landmarks such as the Plaza Hotel, St. Patrick's Cathedral, the New York Public Library, the Empire State Building and the Flatiron Building go by (not to mention Forbes HQ).

By night, he'll take advantage of the lighter traffic and synchronized traffic lights to achieve near warp speed before screeching to a stop at the brightly lit Washington Square Arch. Step into Mario Batali's Otto (1 Fifth Avenue) to recover with a glass of good red wine and a pizza.

Stick out your hand at the right time of day and five or more black-and-yellow taxis will cut across traffic to compete for your business. On this ride you start near the grave of Eva Perón (have coffee in one of the many pleasant cafes outside the cemetery gate) and cut through the Retiro, one of BA's most chic and European-style neighborhoods, on your way to Avenida Nueve de Julio.

Talk about a major thoroughfare: At 425 feet wide, it's said to be the world's widest street. As you're dropped off at the ornate Teatro Colón (take the tour), you'll notice the imposing Obelisk at the Plaza de la Republica. Huge though it may be, its scale shrinks in the middle of such a grand boulevard.

Sprawling Beijing is a great taxi city. Cheap, fast and numerous (there are 66,000), taxis are the best way to get around, especially when you discover how surprisingly small the subway system is. On this ride, you start at the big new hotel and shopping zone and zip past the old foreign legations (site of the siege of the Boxer Rebellion) until your taxi shoots right across the top of Tiananmen Square.

On your left is the vast plaza ringed by government buildings and Mao's impressive tomb. On your right is the bright red main gate of the Forbidden City, with the iconic image of Chairman Mao keeping a watchful eye over the square. Continue along to some of the old-style hutong neighborhoods, where you can hop out and continue your journey in a bicycle rickshaw with a guide who will show you around some of the city's rapidly disappearing back alleys.

Your taxi driver doesn't need your directions; after all, he has The Knowledge -- the comprehensive street sense that all drivers must possess to get a license. But to get a quick look at three centuries of London architecture and a feel for the bustle of the city, head along Oxford Street and turn onto the elegant curve of Regent Street.

After the flash of Piccadilly Circus and a bit of Haymarket, go around Trafalgar Square and down Whitehall, with British government buildings lining both sides. You'll head right for Parliament and Big Ben and then go over Westminster Bridge to the world's most impressive Ferris wheel. From its 443-foot pinnacle you can easily see the entire route you've just taken.

After beginning your ride, it's amazing how quickly the tiny candy-colored city of Reykjavik falls away and you find yourself cruising across a stunningly desolate landscape of treeless lava fields that tumble to the sea. Forty minutes later, you pull into a parking lot and spot clouds of steam rising from behind a small lava mountain. Head down the path carved through the lava for the soak of a lifetime. You can even continue right on to the airport when you're done. It's the perfect way to say goodbye (or hello) to Iceland.

You may find yourself in the back seat of a Mercedes as you take this relatively quick ride along some of Paris's most famous boulevards, an equally compelling trip by day or night. From the bustling tourist area just north of Notre Dame, you head west, with the majesty of the Louvre flashing by on your left and then the shopping arcades of the Rue de Rivoli on your right. At the majestic Place de la Concorde you pass the Hôtel de Crillon and then speed along the magnificent 1.25 miles of the Avenue des Champs-Elysees to the Arc de Triomphe. Stroll back to Louis Vuitton for an authentic taste of Parisian shopping madness.

In this pulsating city, 18,000 little yellow Fiats (called "taksis," appropriately enough) dart through traffic on the ancient hilly streets. This ride starts at busy Taksim Square and heads downhill along the main thoroughfare, Istiklal Caddesi, past countless shops and restaurants, with occasional views of the Bosphorus ahead and off to your left.

Crossing the Golden Horn on the Galata Bridge you can see the minarets of several mosques including the Hagia Sophia, but you'll lose sight of them as the car plunges into the narrow winding streets of the old town. Get out at the spectacular Blue Mosque, ignore the touts, take off your shoes and explore the awe-inspiring tile work inside.

In a city where, as Robert Benchley memorably noted, the streets are full of water, your taxi will be a boat. Sleek, private water-taxis are available at several spots throughout Venice, and the mahogany beauties are a primary means of transportation between Marco Polo Airport and the city center. These are unique and memorable taxis for a unique and memorable city, but be prepared to pay. Just note that it'll cost close to $100 for even a short ride, since rides from the railway station to a nearby hotel start at 60 euros).