bringing in snacks is something that i think everyone does, but just remember the more you take along the more you have to drag every where you go.
I like to keep it simple. Everyone gets their own fanny pack. In each fanny pack is a baggie of various goodies. my personal favs are ; cookies, pretzel sticks , skittles(they don't melt easily), licorice, and at least a sucker or two. Along with this I put one frozen juice box . The right combination of saltly and sweet will calm those sudden cravings for expensive snack foods. You can also try putting dried foods and nuts in the baggies. You can premake these baggies and put them in your suitcases before you leave from home and label them for each individual person. this is a great pretrip activity for the kids.