Webinars. They must engage the audience. Recording the plenary sessions from your Annual Conference and letting people watch them on the web is about as useful as letting them read your committee reports. There are fundamental differences between the way you deliver education from a podium to a room of four thousand people and the way you deliver it over the Internet to a single individual sitting at his/her computer. Respect those differences.
Live Workshops. Schedule them so that no more than 20% of the time is spent in presentation mode and at least 80% of the time is spent with the participants interacting with each other. Trust me. If the room is filled with my peers, I can learn more and more quickly from interactive discussion than I can from listening to 75 minutes of didactic presentation. Really. I'm not kidding.
Special bonus thought on association board meetings. The same 20/80 rule applies. Yes, the CEO should makes sure the board members have accurate information and that their discussions are framed correctly. But then he/she should facilitate interaction by as many board members as possible. Talk less. Listen more.