We have one of these and someone put a piece of a popsicle stick and wrote "Rock Concert" - Love Rock Art.Garden Trinkets - Awesome Ideas, Projects and Tutorials! Including, from 'instructables', this creative 'garden thing' project with rocks.
Step by step instructions for making a precast pebble mosaic (cast inside a frame) . stones are grouted, then backed with concrete - great method for creating custom garden pieces! posted by Ward's Island Community Pebble Mosaic Project: