Andy Davis and Melissa Henige stopped by the office here at Isthmus today. Introducing themselves as the principals of Changing Gears, they described their cross-country bicycle route to gather information regarding what different municipalities and individuals are doing to promote sustainability in their communities. The duo intend to document their expedition on film and and in the blog they're maintaining on their web site at http://changinggearsmovie.com/. The two are in Madison for a few days, meeting with some of the city's leading proponents of sustainability. Their ultimate goal is to take everything they learn on their ride back to their starting point in Bloomington, Indiana, where they hope to seek ways to apply what they've found along their route.