simulations

After reading all of the posts in this week's discussion on simulations it has started me wondering how I could use simulations to enhance library skills instruction. It is easy to imagine how I can use the computer to enhance research. Several of our classmates posted some great links. I wonder though, outside of using the computer, how I can make learning about something like Dewey more hands on. I know, technically speaking, practicing using the library is as hands on as it gets. The concept of Dewey though is somewhat overwhelming to the student's at my school, most on a 3rd grade reading level or lower and with corresponding difficulties in math. I'm just wondering if I can somehow use simulations to make it simpler.