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 awesome costume to their page and if you win you will get a free cupcake everyday for the rest of 2010. Submit your photos by midnight October 31st to win.