In the upcoming era of JWST and 30-meter class ground-based telescopes we will be forced to reckon with the full 3-D nature of extrasolar planets. Today, many current models treat exoplanet atmospheres in one dimension, as a vertically stratified global average — similar to 1-D models of stars and many solar system planets. Yet we know that close-in transiting exoplanets in particular are expected to be tidally locked to their host stars with short radiative timescales in their atmospheres, and should therefore have strong longitudinal inhomogeneities in their temperature structure, composition, and atmospheric dynamics. I will present models and observations of exoplanet atmospheres that take into account their 3-D structure, focusing on how we can recover key physical, chemical, and dynamical properties. I will spend considerable time discussing the constraints on atmospheric circulation that can be obtained through high resolution spectroscopy (R~10^5), which allows for individual spectral lines to be resolved and for atmospheric motions to be directly probed through Doppler-shifted line profiles. This observational technique will reach its full potential with the planned complement of high-resolution spectrographs on upcoming 30-meter class ground-based telescopes.