Flatliners: all the airlines are touting fully flat "sleeper" seats in first class. What's the deal?

Seat dimensions vary between airlines, so that depends on which features matter to you. Continental's BusinessFirst section provides the widest seals at 56 centimeters. Varig boasts the longest beds, at 203 centimeters. The BusinessElite section on Delta flights offers the most reclining seats, at 52. The distance from seat to seat--a measure from the center of each seat--is best on American Airlines, at up to 226 centimeters. TAM says that its seats recline 180 degrees to a completely flat position, as do seats on American and on Varig.

But which numbers really matter? "Americans have gotten bigger, heavier, taller, wider," says Terry Stentz, clinical director at the Somnos Sleep Disorder Center in Lincoln, Nebraska, and an associate professor at the University of Nebraska. "Most of the airline seating I've used is not suited for the direction the height weight distribution has gone in this country." More important than a seal that reclines completely might be the size of the seats. (In fact, lying completely flat can exacerbate obstructions in your airway, increasing snoring and sleep apnea.) Stentz says that even the widest of the seats being advertised may still be too narrow for much of the general population, particularly men. His advice to the airlines? "The most advanced thing the airline people could do is get involved in sleep science and ergonomics, and be learners," Stentz says.

Is it better to rent a phone while traveling or pay the roaming charges?

Erasmo Rojas, director of Latin America and the Caribbean at industry group 3G Americas, which represents GSM wireless technology companies, says that a major deciding factor is whether you want to be the originator or the recipient of calls. If you must be easily accessible, using your own phone and paying the roaming charges is the best option. This way, you keep your regular phone number and those who call you won't pay extra charges. Travelers who primarily need to place calls may be better served by renting a phone with a local number once abroad.

If you've decided you want to take your own phone, you must research several other factors. First, determine what networks are present in your destination, and then find out if your local carrier has a roaming agreement with those carriers. Also, make sure that your phone is compatible with the the country you'll be in--a quad-band phone is especially useful in many South American countries. Finally, don't forget to enable international capability through your local provider before leaving. Frequent travelers should consider upgrading to a flat monthly fee for international service, which offer lower per-minute rates.