When you see someone wandering all over the street because they are on the phone, it is irksome. When you have to reply to a text, not so much.
At Science 2.0 we call this phenomenon "mobile drift" but the American Academy of Orthopaedic Surgeons lumps such mobile deadwalkers under the term "distracted walking." They find that more than three quarters (78 percent) of U.S. adults believe that distracted walking is a "serious" issue; however, 74 percent of Americans say "other people" are usually or always walking while distracted, while only 29 percent say the same about themselves.