Don't give the presenters rum until after their presentations.

Nah, you don't really need anything. Something to take notes. Other than that, be ready to network, ask questions, engage. Lots of people go, stand in the corner, sit in the sessions, don't talk to anyone, leave, and wonder what the big deal is. You absolutely have to plan on talking to people. That's the most important part of the event. The learning is secondary (but important too).