My original training was in theoretical physics: I took a Physics PhD (also at Oxford) before my interests took me towards more conceptual and foundational questions in physics, and from there into philosophy.
My research interests are mostly in the philosophy of physics. I've been particularly active in trying to develop and defend the Everett interpretation of quantum theory (often called the "Many-Worlds Interpretation"); my book on the Everett interpretation, "The Emergent Multiverse", is due out in Spring 2012. But I also have philosophical and conceptual interests in quantum mechanics, quantum field theory, statistical mechanics, general relativity, symmetry and gauge theory, and basically pretty much all of contemporary philosophy of physics. Outside philosophy of physics, I'm interested in emergence and reductionism, in structural realism, and in decision theory.
On the teaching side of my job, I spend the bulk of my time with the Physics and Philosophy and Maths and Philosophy students at Balliol College, and with philosophy of physics teaching across Oxford University. If you're interested in studying at Oxford in general, or Balliol in particular, see here. If you're a current student of mine, my teaching website is here.
I like cats and dinosaurs, but don't currently own any of either.