The key is that you have to be an active participant, either by speaking, by sitting on a panel, or in some other way interacting with other attendees on a formal basis.
Like Jeremy I have moved into a presenter role, my most recent being at Siebel User Week in October. Preparing for a presentation takes time and unless you are trying to sell something there isn’t always an immediate benefit. The benefit to me, beyond honing my speaking skills, is that by presenting I now become a magnet for people coming to me to talk about a topic, usually one I have an interest in as well. It’s such an incredible learning opportunity.
When someone from my team attends a conference I try to make sure they are involved in some way other than just an attendee. While you would like to think everyone is mingling and socializing it just doesn’t happen for many – without that forced interaction you will gain little over a web conference.
Unfortunately budgets have been tight for conferences. I’m looking forward to that improving soon…