After seeing some of the very good work here on DeviantArt, I thought I would try my hand at building cardboard armor. This is the result.
There are 191 pieces of cardboard in the costume, most of which are in the helmet (121). Trash bags cut into strips provide the binding (Idea seen from deviant The-BenT-One). Total build time was about six hours, with most of it used tying the pieces together. Cardboard was obtained for free from work, and I spent $8 on spray paint.
Historical accuracy isn't the strength of this costume, but it got a good reception from the kids I was teaching while wearing it (there were a lot of surprised people in church today when I walked into class).