Airplane or first-class bus line should be the preferred way of travel, at least for tourists visiting Mexico.
Plane, of course.
A great website that tells you the best way and time to travel to Baja, Mexico on a budget would be at gomexico.about.com/od/.../f/when_to_go_mexico.htm. This website gives you great detail on which way and the best time to travel to Baja, Mexico with a dog on a budget.
What is the best way to travel from Innsbruck to Salva
The Best Way to Travel was created in 1968-07.
Mexico City is IN Mexico; it is the capital of such country.
the best way to travel to Spain is through a plane but to travel within Spain perhaps you should consider the train travel.
Your passport is the best one. On your way back however, you may also use a birth certificate or ID. The problem is not entering Mexico; it is going back into the United States.
Bus lines are pretty accessible to local and foreign tourists alike. If you prefer to pay a higher price for a shorter travel time, there are some charter flights from Cancun to Merida.
As long as you have an American passport, you can enter Mexico. Problem is on your way back to the US. Without a valid proof of citizenship, you will not be abe to return to US soil.
you can't travel to Cuba in the USA!
boats
December 1 trough May 30th - out of the hurricane season.