Some things really are more distracting than others

When legislation started covering cell phone usage, many people made the counter-argument that speaking with a passenger should be just as distracting, but the evidence indicated otherwise. Now scientists have some insight into the difference: variations in the signal level of a cell phone in a moving car, even below the level of conscious detection (like few-hundred millisecond gaps), mean that a listener has to work harder to keep track of the conversation. More good reasons for pulling over if you need to use the phone.

(via Follow Me Here)