Hi J.,
The school lunches are actually ALOT better than what you may think. They've come a long way since I was in school. What I do with my son, since I had the same problem last year as you with the thermos .... I let him pick 1-2 days a week on the school lunch calendar for the meals he knows for a fact he'll eat & then I pack 'cold' lunches for the other days. That way he gets his 'hot' & 'cold' lunches (and it saves me from straining my brain too hard to create fun new healthy lunches all the time). My son is a fairly picky eater as well & he LOVES the school lunches!
Now-a-days the schools are really cracking down to make much healthier choices for the kids to eat (and the garbage food is quite limited which makes me happy). Every school lunch he's gotten sounds like something he'd have here at home - for example - a chicken patty, green beans, a fruit cup, milk or juice (he always picks milk), mashed potatoes & a cookie or a brownie (and the cookie/brownie are small- i've seen them). That's a great lunch if you ask me!!!
He doesn't like everything the school has to offer, he IS only 6 =0) but it's nice to know that there's a healthy choice there for him when he wants a hot lunch.
But for some creative lunch ideas - check out lunchopolis.com, familyfun.com, parenting.com, parents.com, disneydreamteam.com, amazingmoms.com, etc - there are TONS of ideas out there waiting to be found. Last year I had so much fun with my son and even my husband, coming up with new healthy fun ways for my son for lunch - not only that but it expanded his pallet!!!
Good luck!
C. B.