The uses are many and the resulting containers are both reusable and disposable.
Step 1: What You Need
1 ea 2L Coke bottle or similar.
1 ea Utility Knife
Step 2: What You Do
2. Fit halves together as desired, depending on end function, as shown.
Uses - Terrarium, food storage/protection, yarn holder, hamster wheel (drill air holes), picnic/camping storage, bread box, bug cage, lunch box, etc .....