Reusable containers instead of plastic bags

I used to send my 4-year-old daughter to preschool with her snacks in plastic sandwich bags, but a few weeks ago I decided to try the Take & Toss plastic containers, hoping that she'd bring them home in her snack bag each day so we could reuse them but not quite sure if she'd remember to. But she has -- every day! I've cut my use of sandwich bags dramatically, and we haven't lost a single container or lid. I was so impressed by her ability to bring them home that I've started sending a real spoon on days when she takes yogurt or macaroni & cheese or other foods that require a spoon to eat them, and not one has been left at school.