Working out the carbon footprint of a product is partly about working out the supply chain of its constituent parts. What better way to visualise the geographical journeys of the supply chains of a product than via a Google Map.
SourceMaps lets you build Google Maps showing the supply chains of products, a journey, the ingredients of a recipe or even the items in your shopping basket. Or, as SourceMaps put it, "people have the right to know where things come from and what they are made of."
This video gives a good overview of the type of maps that you can create with SourceMaps.
Sourcemap is an open source project. Anyone can create their own source map and anyone can embed a created source map in their own web page or blog.