  We study contributions from inhomogeneous (patchy) reionization to arcminute
scale ($1000 < \ell < 10,000$) cosmic microwave background (CMB) anisotropies.
We show that inhomogeneities in the ionization fraction, rather than in the
mean density, dominate both the temperature and the polarization power spectra.
Depending on the ionization history and the clustering bias of the ionizing
sources, we find that rms temperature fluctuations range from 2 $\mu$K to 8
$\mu$K and the corresponding values for polarization are over two orders of
magnitude smaller. Reionization can significantly bias cosmological parameter
estimates and degrade gravitational lensing potential reconstruction from
temperature maps but not from polarization maps. We demonstrate that a simple
modeling of the reionization temperature power spectrum may be sufficient to
remove the parameter bias. The high-$\ell$ temperature power spectrum will
contain some limited information about the sources of reionization.
