I rarely do. I feel guilty just taking things, even if they're offered, and now that I have a child, I don't want him to think that he's "owed" or "entitled" to something (not sure that's the correct word). I bring our own snacks and drinks to the hairdresser, even though she provides a beverage bar and has a candy jar (and DS always asks for a lollipop). We just went on a road trip and every hotel offered a "free" breakfast, but DH and I only take food that we eat in the breakfast area. DS, however, being 3 1/2, asked for juice and Froot Loops that he didn't eat, so we guiltily took them with us.
But, being a bit hypocritical, last year at Disney, after checking out of the hotel and going to the MK for the morning, we went back to the food court and filled up our mugs for our drive out to Clearwater. For some reason, we didn't feel as guilty as we usually would.