If you're prone to motion sickness, you're probably familiar with some of the simple steps to quell the nausea, dizziness, and cold sweats that this common problem can trigger. For example, when traveling by car, insist on driving or ride in the front seat. On a boat, stare at the horizon or close your eyes (see "Can you steer clear of motion sickness?" for more). "Motion sickness was long thought to arise from a sensory conflict between your vision, inner ear, and other senses. Now, most