If you work with smaller parts, you can scan them with a flatbed scanner and get very good results. Scanners, unlike a camera, are free from parallax, and will give great accuracies. Normally I will scan with 1200 or more dpi, then import the picture and scale to 8.5 x 11.7 in my cad, and the dimensions are spot on. Other parts that are unscannable, I do what Rich does. Works great.