If you're not a real chameleon of an actor and if you're not one of those guys who can really shape-change themselves all the time one of the ways to keep pushing yourself and keep changing is to be in different kinds of movies.
I've bought pretty much every book ever written about the Alamo and I talk to my friends that I've made over the past 15 20 years. It's just a constant learning and fascinating thing for me.
