The situation: You key in to your hotel room after a stressful business meeting. All you want is an immediate glass of wine to drink while watching the evening news. The problem: You don’t want to open the full bottle of ludicrously overpriced plonk in the minibar. Room service will take 45 minutes to bring you a Saran-wrapped glass filled with Champagne that’s too warm. A growing number of hotels have found a solution to this widespread dilemma: the Plum machine.