United Airlines Mileage Plus VISA cardholders can rack up some serious miles over the next few months. Bank One and United Airlines launched a promotion this month offering double miles for purchases through October 31. To participate in the Double Miles promotion, cardholders should call 1-800-359-8252 by Sept. 5, to register their Mileage Plus credit card. Bank One recently introduced VISA Signature benefits and the United Mileage Plus Platinum Business card. For additional information about the United Mileage Plus Visa card visit www.mileageplusvisa.com.