I spoke on the openning day in one of the big rooms. This was my first talk at a national meeting (though I did do an oral presentation to a small room for the American Society of Hypertension but the room held only about 50 people. This felt like a thousand.
Here is the room before it began to fill:
and here is the talk. To see the real presentation, download and view the powerpoint. Slideshare squashes the animations so the slides don't build right.