If you don't know what costume to Wear this Halloween, here's an idea. Dress up like a Dunkin' Donuts store. This video clip from last year may give you some ideas. Dunkin' Donuts is doing it again, holding a contest this Halloween where you can win $1,000 and a year's worth of coffee if you dress up like . . . Dunkin' Donuts. You can enter the contest by posting a photo of yourself anytime between now and November 1st in your Dunkin' Donuts costume using the hashtag #DunkinDressUpContest.