Would make cute book shelf for classroom library!! Stack colorful filing crates to use as classroom cubbies or shelves! If they were zip-tied, it would move as a unit and be safe! :) (I would use all one color so that it wouldn't be so visually cluttered)
Editable quick reference flip book to help substitutes find the most important info they need about your class at a glance. Print on brightly colored paper and hang in a prominent location near your desk so that a new substitute can easily find it, and have necessary information at his/her fingertips!