Since 2001, Northwest Airlines has lost $2.9 billion, so it obviously is looking for every way it can to save money. And that includes buying wine and liquor in Minnesota, where it's cheaper, and trucking it into Michigan to be placed on planes. Not so fast, say state alcohol wholesalers, state law says Michigan companies have to buy only from them. The airline says that would cost it an additional $3 million a year, and it's fighting the ban. (It did, however, agree to buy its beer in Michigan.) Other airlines fly in booze for their flights, which is perfectly legal, and Northwest did too until it shifted its wide-bodied planes to long-haul flights in the mid-1990s. The matter is now in court.