My TikZ poster
I was to prepare my first scientific poster (for KR 2012) and tried to look up the existing solutions. I did not like Beamer poster, and since I was already quite familiar with TikZ and knew what one can do with it, I have decided to create my own style based on a0poster and TikZ only, and called it fancytikzposter. Then I got into it so much that I developed different poster templates with the possibility of personalizing the look of the poster. See my posters here and here.
If you want to make a poster using my template, download fancytikzposter sources and pdf with instructions (that can be also obtained by compiling the source files):
By now, there are five templates with different node shapes and colors.