Informal education can augment science classroom instruction and draw students to careers in science. The science and engineering expo, created by the Idaho National Engineering and Environmental Laboratory (INEEL), is a high-impact, inquiry-based, informal-education experience that can be replicated. It engages a broad range of students in learning and exploring science, mathematics, engineering, and technology. The expo is aimed toward youth in grades 5?8, teachers, and parents, and it is also of interest to community leaders and learners of all ages. (Contains 3 color photos and 3 figures.)