MILLERSVILLE, Md. -- Jim Seay likes to make people scream. As the president of Premier Rides Inc., one of the pre-eminent roller coaster designers and manufacturers in the world, he does a good job.

If you fancy a wild ride, where better to get one than a roller coaster?! And when better to partake than in summer, which is synonymous with theme parks and fairs? On "The Early Show on Saturday ...

Thrill seekers and amusement park lovers may live for the high-octane rush of launch roller coasters but most probably never consider how they actually work. Some would probably make the mistake of ...