Why haven't I thought of this?? I love the idea. Especially when I send my kids lunch daily, during school. I simply REFUSE to believe that school lunches need to cost $2+ per kid. Oh my!! Hell NO!!!
So... I already bought lunch bags for the kids new school year, but I am making these too.
There are always a few days when the kids say "Oh no, I forgot my lunch bag at school!" A huge no-no with me, but still happens. Here is the site I found the idea on, and the idea itself... I will share pics of my bags soon. I think I might add do-dads to the outside. Embellishments are in the plenty around this house.

Oh and I am talking about the bag itself, not the felt food. LOL
http://www.skiptomylou.org/2009/03/09/felt-brown-bag-lunch-tutorial/

I also think I will get a little larger felt square, as the bags might be a bit too small with regular felt squares. Felt is sold by the yard at the fabric store too. You can also buy clear tablecloth vinyl and make a lining for the bags. A little better to clean up the things the kids leave behind. :)