  We present science highlights and performance from the Swift X-ray Telescope
(XRT), which was launched on November 20, 2004. The XRT covers the 0.2-10 keV
band, and spends most of its time observing gamma-ray burst (GRB)afterglows,
though it has also performed observations of many other objects. By mid-August
2007, the XRT had observed over 220 GRB afterglows, detecting about 96% of
them. The XRT positions enable followup ground-based optical observations, with
roughly 60% of the afterglows detected at optical or near IR wavelengths.
Redshifts are measured for 33% of X-ray afterglows. Science highlights include
the discovery of flaring behavior at quite late times, with implications for
GRB central engines; localization of short GRBs, leading to observational
support for compact merger progenitors for this class of bursts; a mysterious
plateau phase to GRB afterglows; as well as many other interesting observations
such as X-ray emission from comets, novae, galactic transients, and other
objects.
