Kudos to you for doing Paleo lunches for your kids. I do a semi-Primal lunch for my 5 and 3.5 year old. I do make sandwiches with bread, but often they just eat the meat from the middle anyway.

nomnompaleo.com recently did a write-up with a week of kid lunch options here: http://nomnompaleo.com/post/30267255011/a-week-of-paleo-school-lunches-part-1-of-5

I use Planetboxes with my boys, which they love. www.planetbox.com

meat and cheese roll-ups, sliced fruit/berries, sliced veggies with some sort of dip, leftover dinner...

Nom nom paleo has great ideas. I don't have kids but I used that post to help me with my own lunches.

I like to do the meat and cheese rollups, or chicken strip dipped in something (which totally works cold), fruit salad is always fun. I also do leftovers and will bring soups in my insulated lunchbot. You do have to let it sit with hot water about 5min and heat your food before filling which is kind of a pain, but I've packed up chili at 7am, didn't have lunch until 1p and the chili was still warm enough to melt the cheese I sprinkled on it.

My new favorite (non leftover) paleo lunch:
spring mix
can of tuna, drained
100 cal packet of spicy wholly guac
drizzle of olive oil

Easy, quick and delicious for the win!

Why not just leftover dinner for lunch? If you pre-bake a big batch of chicken drumsticks, they make fun easy lunches as well. Other ideas include:
- celery and almond butter
- paleo sushi (if they are creative eaters)
- Sausage sliced on cucumber
- carrot and veggies and an avocado/guacamole dip of sorts
- For a sweet treat: yam baked with cinnamon and honey
- paleo granola bars

Ya, we're all about leftovers. Every night we make a big batch of food for dinner and just bring leftovers for lunch.

Get a crockpot and make a bit batch of chili. Instead of beans buy a bunch of carrots, peppers and onions and add them in.

Another crockpot idea - shred the meat from a leftover roast and coat it in homemade barbeque sauce in the crockpot. Voila! BBQ beef!

Also - LETTUCE WRAP ALL THE THINGS!

Seriously, want something a little more substantial than meat and cheese rolls? Toss it in a big leaf of lettuce, add other toppings to taste and either use another piece of lettuce or wrap the lettuce around like a burrito.

Also, salads work well, too. Add chopped up meat to a bed of your favorite lettuces, add some nuts, seeds, hard boiled egg, and other toppings of your choice, finish with a good oil dressing of your choice, and you have a nice light but filling lunch.

I second the planet box. I have a launch, and my kids both have rovers. I do salad just about everyday for lunch with leftover meat from the night before.