This script lets you paint objects (geometry, splines, lights, helpers, etc) onto a piece of geometry. Like for example, you can make 10 different rocks, and then paint them in a random fashion onto a terrain.
Make a plane with many segments, apply a nosie modifier to make it hilly. Create a sphere, a cylinder and a box. Run the UI version of the script. Select the plane, click the "Add Selection To Paint On List" Button. The plane is added to the list. Select the 3 other objects, click the "Add Selection To Paint With List" button. Those 3 objects get added to