I found this device advertised in the back of Lawn & Landscape Magazine. http://www.measurearea.com/index.html It's supposed to calculate the square footage of an odd shaped area simply by running the wheel around it. Does anyone have any experience with this device? Or better yet does anyone know the correct mathematical formula for calculating the square footage of an odd shaped area, like a kidney shaped garden bed? There has to be a better way then "rounding the area off to a rectangle or square".