Out of Google's Area 120, which is an incubator for ideas, apps, and services, there's a new app called Stack available to those with an Android device. With it, you can scan any sort of document with your phone's camera, then the app can automatically sort and organize (or Stack) said document for you. Since its still early days, you can expect some errors. As Google details, "It's early days -- our algorithms still get things wrong, but we're improving them every day." However, should everything be working smoothly, you can scan a receipt, with the app automatically recognizing that it is indeed a receipt and filing it away as such for access later on.