I really enjoy tofu! There are lots of great ways to use tofu, and there are many different types of tofu that you can eat.
One of the easiest things to do with it is make a tofu scramble, which is basically scrambled eggs with veggies and cheese w/ the tofu in place of the eggs. The consistancy is almost exactly the same as scrambled eggs. Lots of protein, much less fat and cholesterol.
It is also really easy to marinade and bake. I did a ginger soy marinade once, and it was pretty yummy. Tofu in and of itself doesn't have a flavor, so it really easily absorbs whatever flavor you give it. I've also cubed it and thrown it into stirfrys with some sauce (although more marinading = more flavor).
We also buy alot of prepackaged baked tofu just because it is so quick and easy to make. You can get tons of flavors too... carribean, asian, smoked, savory, etc. I usually just slice it length wise and then in half to get four more slender pieces, and then fry it in a little olive oil for a few minutes on both sides until it is a little crispy on the outside. I swear, it is really yummy!
In terms of including it in your kids lunch boxes, I think it would be difficult to include it as a separate item, especially if it cannot be heated up. However, I did make a veggie and tofu pasta dish last Friday that actually tasted really good the next day unheated. The tofu was crumbled up pretty finely and almost disappeared as a sauce, so it worked really well as a cold leftover. I think it would be able to work in a lunchbox as long as it was a part of a bigger dish.