I stumbled on these cool free homeschool ID card. Get them here.
I printed mine out on photo paper and then decided that I still wanted them to be thicker. So I glued them to some cardboard and quickly laminated them with packing tape. This also made it possible for me to punch a hole through the cardboard so the kids could hang their IDs on lanyards.
I can't really think of a good reason why they will NEED their ID cards, but they sure look cool and they are really excited to have them!