If you've been to an airport lately, you've probably noticed that air travel is becoming more and more congested. Despite frequent delays, airplanes still provide the fastest way to travel hundreds or thousands of miles. Passenger air travel revolutionized the transportation industry in the last century, letting people traverse great distances in a matter of hours instead of days or weeks.

The only alternatives to airplanes -- feet, cars, buses, boats and conventional trains -- are just too slow for today's fast-paced society. However, there is a new form of transportation on the horizon that will revolutionize transportation of the 21st century the way airplanes did in the 20th century.

Photo courtesy Railway Technical Research Institute
Traveling at speeds of up to 300 mph (500 kph), maglev trains could begin connecting distant cities as soon as 2004.

At least two countries are using powerful electromagnets to develop high-speed trains, called maglev trains. Maglev is short for magnetic levitation, which means that these trains will float over a guideway using the basic principles of magnets to replace the old steel wheel and track trains. In this edition of HowStuffWorks, you will learn how electromagnetic propulsion works, how two specific types of maglev trains work and when you might be able to ride one of these trains.