In a writeup of the Photoshop World conference, I read about a thing they do called "jam sessions". They're five minute (lightning) talks, but they hold them at the start of the conference and everyone who gives a 45m or 90m talk at the conference plugs the hell out of the their talk for five minutes or less. So by the end, the audience is whipped into a frenzy to attend every damn session! (and has a pretty good idea which presenters are incomprehensible, which are blowhards, etc.).