One ordinary to-do issue that came up at the prayer tent at Occupy DC (#OccupyDC) is signage. Indeed, clear signage -- for intra-camp use, much less for signs and banners in demonstrations -- is an issue.
For which, I'd like to point out a open-source signage font called Allerta.
There's a coordinating font for print pieces; the typeface includes glyphs commonly needed for signs, for "bus", "women", "men", "food", arrows and the like.
The font file (at the link above), the open-source Inkscape software (or Adobe Illustrator), printouts, tracing paper (or the old pencil rubbing on scrap paper trick), some thin board (cereal boxes?) and a craft knife could do wonders.
Alas! there's no Angus Dei/Lamb and Flag for the prayer tent!