In many ways, the role of visualization in science is distinct from other disciplines. Many natural processes--and even some objects--are too small, too fast, too slow, or too far away to view without highly specialized equipment. Of course, students at every grade level can understand a phenomenon better when they can see it. That is why textbooks attempt to illustrate scientific concepts with photographs and diagrams, and science teachers stock their classrooms with microscopes. Teachers have also taken advantage of videotapes and laserdiscs to present a wider variety of visual images to students. The World Wide Web opened access to even more up-to-the-minute, state-of-the-art scientific images. In all these examples, however, the control of the content remains solely with the teacher. The new generation of imaging sensors (such as charge coupled displays, or CCDs) have made digital cameras and other technologies possible that can put the control of image making in the hands of students. This article discusses the following functionality of imaging sensors for students: acquiring; analyzing; creating; and communicating. The article concludes that digital images offer a means of extending and building upon traditional methods of inquiry in science class. The role of the student can shift from passive observer to engaged participant. Benefits include the ability to capture events that would not otherwise be observable, and to share conclusions about such events through images incorporated into science journals and Web sites.