At the beginning of a presentation, the presenter asks for all devices to be either muzzled or turned off. Within minutes, you start hearing the devices notify the various users that they have messages. Why can't people do as they are asked. I think part of the reason for people not turning devices to vibrate is because they feel that their email is more important and bothering people isn't something they care about.
Another thing people do is put their device on the table and let it vibrate, but of course that disrupts other attendees. If you put your device on vibrate, put it in the holster or a pocket and that way it will contact you but not disrupt those around you. It is interesting to hear the different sounds that people have for their settings.
Of course, I am at an all day conference, and it is fun to see what people do at breaks. Besides the basic personal needs, everyone checks their email and voice mail. A 20-minute break seems to disappear very quickly when you do this. Of course, at sponsored events, the 20 minutes is supposed to be used to talk to the sponsoring vendors. Nowadays, to take time away from the office means you still need to contact the office at breaks and at lunch. Even for consultants, the breaks are used for talking with clients.
Agendas are very important for attendees. I am at an event where the agenda was not talked about at the beginning of the day. The agenda is available online, but not visible for those attending without an internet connection. I, for one, decided that I would print the agenda before coming to the event and am glad I did. The agenda does help know when you are going to be able to contact that person who contacted you during the presentation.
It is very important to go to the various conferences and seminars as it does keep you update on what is happening in IT. Most people have a focus, but it is a good idea to attend some seminars outside your focus so that you know what is happening in general. Having a focus is great but remember if you don't think outside your focus, you may lose your focus and have nothing to fall back on.