Bryan Hunt on reminded me on twitter of an interesting article about using Twitter as a participation tool during presentations. I have no idea how many people will be twitter enabled at EclipseCon. However, this article does raise some interesting ideas for presenters to increase audience participation.
As I have mentioned before, the hashcode for EclipseCon is #eclipsecon. Brian is doing a short talk and you can tweet questions to Brian using #emfworkflow.