Drawing a cork is a commitment and a once-opened bottle provokes a dilemma, even for the moderate wine bibbers who read (and write) this column. What if you want to drink no more than a glass and are unlikely to be drinking the next day? A half-full bottle, especially if half-decent, is not going to be up to it two days later. As location, location, location is to property, so oxidation, oxidation, oxidation is to wine, though in only one direction. One of the most common and simplest solutions is the Vacu Vin pump that sucks out air from the bottle, indicating with a click when the vacuum is achieved. Many restaurants are now using sophisticated machines that do the same thing. On this basis, some London establishments report greater sales of even high-end wine by the glass. At one centr