As we consume, we leave stuff behind. We leave behind waste and garbage and refuse. And increasingly, we leave behind mountains of data. ... These are straightforward, almost inescapable, facts of 21st-century consumer life, but they got Indhira Rojas thinking. As a graduate student in the design program of California College of the Arts, Rojas wrote her thesis on the role of design in creating a “zero-waste culture.” This led her to imagine a hypothetical service she has named IndexR, which would mine those retail data mountains and shovel our shopping information back to us in ways that help us become better consumers.