People think they're being polite and attentive by turning their cellphones to "vibrate" mode during conference sessions, but that isn't enough to keep their attention. According to Fast Company, the sound a vibrating phone makes is the third most-addictive noise there is (behind only a baby's giggle and the Intel dum dum dum dum). As the article says, "When we switch our phone into silent mode, we think it cannot be heard. But the vibration has its own sound, and almost immediately the test subjects stopped whatever they were doing to attend to their phones."
The whole article is well worth a read, especially to those of us who wonder where marketing will go next. Which should be every conference planner, because no one puts more time, money, and research into how people learn and how to make learning stick than marketers. Now that they're starting to look into how to reach people through more than just their visual sense, here's hoping we do as well (and we're not even selling anything other than good ideas, right?).