Photo by dracisk.Hello Cupcake will be giving away a free cupcake to those who come into their Dupont shop in costume, today from 4-7 pm. Sounds like a good stop on your way home from the rally, where you’ll likely be exhausted and in need of sugar. And, if you can’t make it today, they are doing a Halloween costume contest that has a pretty sweet prize. Upload a photo of yourself in your…