Slides for our 5 minute Botacon 0 presentation on Nickel for Scale. Nickel for Scale is a Processing app that uses computer vision to measure the sizes of objects in an image, using a nickel to determine the scale. Measurements are then used to customize 3D objects for rapid prototyping machines, such as a MakerBot 3D printer. Nickel for Scale was created in 48 hours by Marty McGuire and Amy Hurst at the first Baltimore Hackathon. Our hope is to demonstrate that with little effort is it possible to create usable customization apps with real-world uses.