Document cameras are located in many of the general purpose and technology enhanced classrooms on campus. With a document camera, you can display documents, books, graphics (e.g., pictures, charts, and maps), and three-dimensional objects and project them so even students in the back of the class can see. In most cases, the same rules that apply to the use of the chalkboard also apply to overhead projectors. Overheads, however, have several advantages — transparencies can be prepared in advance of the class, and it is easier to prepare graphics and pictures for the overhead than for the chalkboard.