Image Blogs to help categorize

Students love to photograph things. Many students are comfortable with uploading photos to digital photography portals like flickr. What a better way to sum up a lesson on physical versus chemical change than to have the students upload their own examples? I would set up groups- have some students submit photos, other students sort using the comments section and a third group will agree, disagree or add a comment. For example, the title will read "Is this photo showing a physical or chemical change" and then students make comment, i.e., brown leaves- chemical change,-decomposition or person painting room- physical change just covering the surface. Here is a link to an environmental/science related site in California which is worth watching for ideas: Link http://www.flickr.com/groups/kqedquest