The service fee is supposed to be so that all the staff gets rewarded and not just the wait staff and bartenders. I believe Rob posted on an older thread on this topic that this is a gov't regulation and they have to document this for tax purposes. I still tip the wait and bar staff just as I would here in the states, in cash and in hand. As for housekeeping we make sure to meet our housekeepers and learn their names and schedules. We tip them $5US per day per bed and extra at the end of our stay. Those we have known from year to year also get personalized gifts.