Cartoonist Cameron Stewart is touring North America (with a stop in the United Kingdom) in support of his recently released graphic novel Sin Titulo, and he's been hiding pieces of original art during each of his stops -- along with hints as to where he deposited them. So far Stewart has visited 10 cities in the United States and Canada, with another signing tonight at Chicago's Challenger Comics + Conversation. The Windy City art already been found, but people in Columbus, Ohio, New York City and Leeds, England, need to stay tuned to Stewart's blog as he drops more clues. Here are the details of Stewart's tour so you can get ready.