United MileagePlus Half-Million Mile Sweepstakes

United MileagePlus is running a 500,000 mile sweepstakes, giving away 25,000 miles each to 20 lucky winners. To register, you can sign up here by Sept 30, 2012 and you can get additional entries by doing things like signing up for email communications, shopping at the United MileagePlus website, and viewing additional merchant offers. Good luck to all!