I did a really crappy programmer's version as a first step; see here:
http://barcampmontreal.org/wiki/Image:BarCampMontreal3_flier.png
If it hurts your eyes to look at that, please upload another version of
the SVG source, here!
http://barcampmontreal.org/wiki/Image:BarCampMontreal3_flier.svg
-Evan