If you need any proof that the strength of the advertising business lies in its creativity, look no further than the fun costumes the industry donned for Halloween 2011. Many of them paid homage to their favorite brand mascots (Sprout) and pitchmen (or, women, like Progressive 's Flo), while several showed their love for classic brands. There were handmade costumes such as an Etch-a-Sketch toy and a Polaroid camera. Our favorite, though, was a costume that was a Words with Friends app, complete with velcro letters that could be moved around to actually play the game. Enjoy the photos they sent in to us. And maybe you'll get some inspiration for next year.