For most sauces (mayo, salsa, ketchup) I go with McDonalds since they're everywhere.
When I forget TP and remember on the way to the trail, any large fast food chain will do. Actually, the stuff they use in those huge rolls is super thin and I bet it weighs a lot less per yard then the stuff you probably use from home. It seems a bit hard on the underside to use regularly but who knows. If you snatched one of those big rolls and took it home, you'd have a lifetime supply of ultralight toilet paper. Actually, on my first backpacking trip ever (probably 10-12 year ago) I forgot TP so I clipped one of those huge rolls to the outside of my pack. It was probably 5 lbs of TP (take that Mike C!). I balanced it out with a huge bundle of banana's clipped to the other side.
For cutlery the cheap plastic fast food stuff works in a pinch, but it's a gamble on a longer trip since you'll likely break it. McD's McFlurry spoons or Dairy Queen spoons are your best best for lightweight and durable.
White Spot here in Western Canada has amazing take home containers for your leftover food. They are quality, lightweight plastic containers that can easily be used as a bowl/mug. Just be sure to ask that they cram your leftovers into a small one....or just leave 2 fries on your plate and ask that they pack that up :)