One of the things that made 2012 such a joyous and wonderful year was the popularization of Instagram, the smartphone app that allows anyone with an iPhone and Android (sorry, BB users) to snap a picture on the go, apply one of a handful of filters, and post pictures for the world to harvest in their history of "Liked" photos. We've come a long way since Polaroids and disposable cameras. And thankfully, models, actresses, and socialites alike have caught onto the trend and added their two cents to the photo-sharing frenzy. Take a look back at some of the sexiest celebrities of 2012, in Instagram photos. You're in for a real treat!