St. Collins Lane Shopping Centre, at 260 Collins Street, Melbourne, will be giving away 500 Dessert Parlour "holographic" doughnuts, with 250 available at 12:30pm, and another 250 available at 5pm on Friday August 31. If you get your timing right, you can also walk a short distance and hopefully obtain a free AMEX contactless band as well.
1 Doughnut per person while stocks last.
I'd expect lines to be an hour, as they're likely to get you to sign up for their newsletter.