I suggest that the greater emphasis be placed on showing the concepts about how a rasterized painting (Photoshop) program can manipulate any digitized image that your students can acquire (drawing on Wacom or Pablo digital tablets, scanning existing pictures on flat-bed scanner, traditional film scanned onto Kodak PictureCD and PhotoCD, files uploaded from digital camera, etc.). After they are aware of Photoshop's capabilities, then they can better judge the capabilities of the less expensive software to manipulate images. Teach the difference between bitmap raster paint programs (Adobe Photoshop, Microsoft Paint, Corel Photo-Paint, Micrografx Picture Publisher, Ulead PhotoImpact, etc.) and vector drawing programs (Adobe Illustrator, Macromedia Freehand, CorelDraw). Information is necessary about how to choose a file size appropriate for the desired output device. College-level textbooks are available about digital image processing, to explain the inner workings of digital filters and why certain filters might be more appropriate for the given data. Kodak authored a textbook about color management theory, necessary information for calibrating the various devices used. The technology is changing so rapidly that experience with old technology doesn't count for much in graphic design arts, and conceptualization about how a result can be obtained with least computation is more important. The computer is crunching on the strings of numbers that represent the image. A common underlying thread could be how to recognize a well-designed, well-executed, well-processed image. Make certain that the kids get to shoot endless quantities of images. Gotta keep them happily snapping away every day, while you trick them into learning something useful during the process. My personal favorite of digital cameras is the Sony Mavica series, that use ubiquitous and cheap 3.5-inch diskettes