I am having the pleasure of preparing a poster for IJCAI 2011, for the first time in my life. Both the IJCAI and a poster. Fiddling with PowerPoint or Illustrator is painful. Beautiful slides can be prepared with S5 using HTML and CSS; a poster in HTML and CSS is also worth a try.
Here is my HTML and CSS conference poster. Topics zoom in and out when you click on them. A PDF version for printing is also two clicks away in a decent web browser (that is, Mozilla Firefox).
I am less fearful of preparing conference posters now.