Great idea for lunches -- make smoothies, freeze them, then put them in their lunchboxes frozen (they will thaw before lunch plus act as a cold pack for other things). remember to put a straw in the lunchbox! Lots of other great snack/lunch ideas on here!
OMG- so doing this: 4 Growing Boys: School lunch ideas--great ideas. Pack on weekends. Ready for the week. Jello right into the container to set up. Lots of quick tips, even if you don't use these containers.