In-room spa services are on a roll. Newly designed carts that hold everything needed for facials, massages and more are bringing treatments to guestrooms at Michigan's JW Marriott Grand Rapids. Even better, prices are no more than in the hotel's spa. The spas on wheels — which may soon be seen at more hotels — can turn each of the JW Marriott's 337 rooms and suites into a sanctum "where guests can crawl off the table and get into bed," says Vickie Bennett, whose Vasaio Life Spa provides the hotel's spa services. She designed the carts with husband Victor to expand on the tiny spa area and in response to guests who crave privacy or hate to get dressed and toddle back to their rooms after relaxing treatments.