Around 2005, a petition started circulating by email among Quebecers. It was something about the Charest government wanting to ban arts from the school curiculum. Recipients were instructed to add their name to the bottom of the mail, and then forward it to everyone they knew. Soon everybody in Quebec was forwarding it to all their friends. I received several copies from unrelated people.
Of course, this is technically a rather silly approach, because the petition grew as a complex graph of signatures, rather than a straightforward list, as well-behaved petitions do. Every copy of the petition you'd receive would start out with the same names, then fork off at some point, and eventually come back to you through its own path. I thought it'd be cool to map out the paths taken by the petition.
I collected as many samples of the petition as I could find, either from my own inbox, through Googling, or with the help of friends (You can still help! Search your inbox for "arts secondaire" and forward me any copy you find!). Then I aligned them by putting them side by side and merging identical names. Then I printed it out as a tree. Looks like this:
There's a lot of room for experimentation with cooler visualization techniques, here, starting perhaps with a tree representation that's easier to browser than a 50-megapixel image. Perhaps one could also look at social patterns of email chain propagation, though we don't have much data about the people involved. We do have a town name for most of them, so we could try and plot on a map the geographical travels of the petition.
(Oh, and as it turns out, the Quebec government never did intend to take away arts from high schools)