Our friends brought all the fixings for a pasta dinner when we brought them with us for the marathon. They did all the cooking for that meal and cleaned up afterward. A nice relaxing dinner on an evening when the guys were going to be taking it easy anyway.
We've taken lots of family and friends on our trips. They have all either made a dinner, bought a dinner or just had a great time with us. My BIL watched our son on one evening and insisted that the two of us go out and have a nice dinner alone. No whining, no complaining that they didn't want to do..., no complaining about the cost of the tickets/food/souveniers.
Our son is an only child, so bringing along the others gives him some playmates for the trip.