I don’t do the studies, I just post them, folks:
We investigated the effects of divided attention during walking. Individuals were classified based on whether they were walking while talking on a cell phone, listening to an MP3 player, walking without any electronics or walking in a pair. In the first study, we found that cell phone users walked more slowly, changed directions more frequently, and were less likely to acknowledge other people than individuals in the other conditions. In the second study, we found that cell phone users were less likely to notice an unusual activity along their walking route (a unicycling clown). Cell phone usage may cause inattentional blindness even during a simple activity that should require few cognitive resources
Source: “Did you see the unicycling clown? Inattentional blindness while walking and talking on a cell phone” from Applied Cognitive Psychology
Ha-ha, how silly… Well, there is a serious element here: if talking on a cellphone means you don’t notice unicycling clowns, should you really be driving and talking on one?
Let me word it differently: do you want those other people — who are not as smart, good-looking, and as excellent a driver as you are — talking on a cellphone and driving? I didn’t think so.