Picking up trash and pulling weeds may not sound terribly posh, but at a growing number of high-end resorts, where rooms often cost $400 or $500 a night, these activities are becoming yet another hotel amenity. One morning you can sleep in and order room service, and the next you can serve breakfast at a soup kitchen.
The trend is part of a larger movement toward voluntourism, i.e., trips with a heavy focus on volunteering. But unlike programs like Habitat for Humanity that pair weeklong projects with unglamorous accommodations, hotel-organized excursions generally take up no more than a day, and participants...