All over!! You can get Mickey ears and assorted hats with ears all over DLR. You will see them at practically every souvenir stand you pass, but they can also be found in the Emporium, World of Disney, Gag Factory, all over the parks in the major (non-specialty) merchandise shops. And what's even more fun is that, if I recall, your trip is taking place just a few days before the Halloween season begins at DLR, so you may be able to find a pair of Halloween ears too! Last year, there were Pumpkin ears, Candy Corn ears and Witch ears (as well as something else I am forgetting). We did not see them at every stand we passed, but we saw them in a couple of random shops in DCA.