The cafeteria in our building uses paper disposables. I imagine you can use your own for the price of a (small?)...but I'm not sure. I never buy coffee there.
There is a "coffee fund" on our floor with a few divisions. You pay into it for coffee, sugar, creamer, but you supply your own mug. Tea drinkers just toss a few nickels in a can for sugar, if that's their thing, I think. I think there are a few extra mugs kicking around for guests.
I drink coffee at home, and when I bike commute, I bring a thermos with coffee and have a mug at my desk.