Since the violent relaxation in hierarchical merging is incomplete, the distribution functions of galaxies contain a wealth of information about their formation pathways. Recent advances in integral field spectroscopy, multi-slit infrared spectroscopy, and dynamical modeling techniques have greatly improved our ability to harvest this information. I will discuss how various formation processes may imprint themselves on the present-day orbital structure of galaxies, with an emphasis on mergers between dynamically cold systems. The merger model predicts a physically intuitive structure that bears a tantalizing resemblance to dynamical models of some observed slowly rotating ellipticals. Simulated merger remnants also show a sharp kinematic transition between ~1 and 3 effective radii, highlighting the importance of large-radius spectroscopic observations for constraining galaxy formation models.