Multitasking: About 2.5% of people can use a cellphone and drive without performing worse at either task, according to a study forthcoming in the Psychonomic Bulletin and Review. The participants, 200 college students, performed a math-and-memorization test and a driving simulation first as single tasks and then simultaneously. While multitasking, they answered the test over a hands-free cellphone. Nearly all the subjects took longer to brake while multitasking and scored lower on the test. But five of the subjects, whom the researchers dubbed 'supertaskers,' could multitask without becoming worse drivers or test-takers. Remarkably, supertaskers also scored better on the test when driving.

Caveat: It's unclear whether supertaskers are more common among older, more experienced drivers, or how directly the findings apply to actual, rather than simulated, driving.