With a few deft maneuvers of the scissor, you can transform an empty milk carton into a reusable sandwich or snack box.
Marker up a milk carton like in the picture at left. Draw a straight dotted line around the bottom that connects the bottom of each arch. Cut out the negative spaces. Waggle the sides back and forth. Then fold the top down and use an adhesive-backed Velcro dot to create the seal for the lid.
Cheaper than Tupperware or Ziploc bags!
Reusable Lunch Containers [FamilyFun]