The folks at Everyday Paleo use these metal lunch boxes by Planet Box which are a bit costly, but seem well worth it. I don't have kids [yet :)], but sometimes pack lunches for myself using the BPA-free Bento-style boxes from Laptop Lunches. I purchased different inner containers so I don't have to wash them every single day to reuse them. Note that the portion size is good for someone like me who eats a standard-sized lunch, or a school child. Larger adults (e.g. my husband) may find these containers too small for their larger appetites.
I got really interested in Japanese Bento box culture a few years back which prompted me to purchase this set for myself. Some Japanese parents get really creative in how they arrange their children's lunches, even forming some of the food into shapes and characters. They're not just for kids, though. Many people make it a form of art and attempt to put together elaborate lunches to impress others. Unforunately, their recipes usually have a lot of rice and other non-Paleo ingredients, but it's still fun to look at the photos and get ideas of your own. Here is an interesting link to read up more on packing Japanese Bento boxes.
Here is an example of an elaborate Japanese bento:
Here are some of my own actual lunches I've packed using my trusty Bento box. It was just for me so I didn't feel a need to make little baby chicks or scenes of trains. If you store the box in an insulated bag with an ice pack, the box will keep for several hours and nothing inside requires heating in a microwave (although you could heat something up if you had access to one).
|chicken salad lettuce wraps (homemade mayo), baby carrots, mango slices|
|green salad with hard boiled eggs and mango slices|
|tuna salad lettuce wraps (homemade mayo) with guacamole-stuffed tomato and kiwi slices|
|steak salad with broccoli florets and sliced kiwi|
|pesto chicken lettuce wraps with baby carrots, celery sticks and kiwi slices|