If you missed out on the Philly Brick Fest 2014 deal a few weeks ago on Amazon Local, there is another one going on Living Social. For $20, you get a one day entry to the convention as well as a free t-shirt.
Remember, the organizers of Philly Brick Fest also have an art contest going for you to design their program cover. The winner will get a $100 LEGO Gift Card. See all the official rules here.