For U.S. Readers: Free Coroplast Grids!
But more important, don't forget to help clean up any coroplast campaign signs that are still standing in your area tomorrow.
They are nothing but landfill fodder after the polls close, and they make great DIY gridspot raw material. Black is best (no internal reflections) but white is doable, too. Avoid colors - they give you a color cast.
In fact, Strobist reader Leann has a neat little tutorial for making coroplast gridspots that make my little cardboard jobbies look like crap.
The advantage to my version was that they were free. But it's practically raining free coroplast tomorrow morning, and you certainly don't wanna miss out on that.