3D scanners can turn everyday objects into 3D images for easy manipulation on a computer. Scanning is one of the easiest and quickest ways to create a printable design file for a 3D object. The alternatives include downloading a file created by someone else, and using software to design a model from scratch.
Initially 3d scanners were expensive specialty items but there are now a number of affordable 3D scanners making their way on to the market. There are also DIY scanners, with downloadable plans, that use 3D imaging devices like the camera in Microsoft's Xbox Kinect.