Cosmic acceleration at early and late times are two of the biggest
mysteries confronting cosmologists today. The initial conditions of the
Big-Bang are thought to have been set during ``inflation'', an era of
almost exponential expansion in the primordial universe. Inflation also
provides a mechanism to generate the primordial fluctuations, anisotropies
imprinted into the cosmic microwave background (CMB) radiation which
result in the rich structure of matter today. Current cosmological data
are, for the first time, precise enough to allow detailed observational
tests of inflationary models. I will describe efforts to understand the
microphysics of inflation, focusing in particular on CMB data.

Intriguingly, several independent data sets show that the cosmological
expansion may be once again accelerating. These observations lead to the
conclusion that the universe is dominated by a negative-pressure
component, ``dark energy'', which makes up roughly three-quarters of the
cosmological energy density. Theoretical models for the dark energy
include Einstein's cosmological constant, a dynamical component, etc. I
will show how tools for extracting information about inflationary models
can be used to constrain the physics of dark energy.