Popcorn - microwave bags are easy. If the daycare has a microwave they can do it there, or you can nuke a couple bags and then bring them.
Apple slices - we have a corer/slicer that makes 8 apple slices (or pear slices) in a flash. (It's what we brought to J's classroom Valentine's Day party instead of the sweet stuff, and they got DEVOURED!
Bananas cut in half (keep the peel on till ready to serve).
Cheap party favors from some place like Party City (if you have something like that near you) or maybe Michael's.
Carrot sticks with dip - you can often get that at your grocery in a box. Carrots and cucumber slices also dip well in guacamole - YUMMY!!!!
Raisins - our groceries also carry multi-packs of tiny boxes of raisins for packing in lunches.
Veggie chips/sticks.
Dried fruit, like papaya or mango; can often find this at the grocery store too. (Note: these are usually sweetened, so the parents who have issues with sweets might also have a problem witht he added sugar.)
YoBaby yogurt cups - you can buy them in 6-packs, I think. (Again, they often have added sugar, but at least I think it's organic so not highly processed.)
Cheese and crackers. Cheese sticks too!
(I confess to being a parent who is kind of a sugar Nazi, so I have lots of these ideas!)