One of the neatest things you can equip your kiddos' with for when they are out in the "wild" is an adventure bag full of fun.
I whipped up these bags from scrap fabric pieces and burlap I had floating about but you can use any pre-made bag. Having a strap so that the bag hangs cross-wise over the body is probably best. That is how both ander and zaza wore theirs. One that is not-so-fancy and water proof-ish is a good idea as well.
Here's what we put inside the bags:
*pack of gum
*handmade book or notebook
*small plastic baggies for collecting
*pencil & sharpener
*index cars & tags