  We present the results of recent observations of phase-dependent variations
in brightness designed to characterize the atmospheres of hot Jupiters. In
particular, we focus on recent observations of the transiting planet HD 189733b
at 8 micron using the Spitzer Space Telescope, which allow us to determine the
efficiency of the day-night circulation on this planet and estimate the
longitudinal positions of hot and cold regions in the atmosphere. We discuss
the implications of these observations in the context of two other successful
detections of more sparsely-sampled phase variations for the non-transiting
systems upsilon And b and HD 179949b, which imply a potential diversity in the
properties of the atmospheres of hot Jupiters. Lastly, we highlight several
upcoming Spitzer observations that will extend this sample to additional
wavelengths and more transiting systems in the near future.
