I struggle with tipping in general, especially restaurants. (How much tip do you give when you're at a smorgasboard? Why should the server bringing me steak get a bigger tip than the server bringing me a salad?).

If I'm on a per-diem, I'll leave a few bucks in appreciation but I've come up with a clever solution for the ol' expense account situation. I often stop by a grocery store and pick up a salad for supper. It never comes close to the budgeted amount, so I also pick up some good quality chocolate or cookies. I leave these for the cleaning staff and, if I visit the hotel frequently, the desk staff.