  Recent X-ray timing and spectral observations of black hole binaries in
outburst have redefined methods for investigating the properties of Galactic
black holes and the physics of accretion flows. High-frequency X-ray QPOs in 5
systems (60--300 Hz) continue to be investigated as a possible means to
constrain black hole mass and spin via interpretation as oscillations due to
strong-field effects in General Relativity. In principle, black hole mass and
spin may also be constrained via determination of the inner radius of the
accretion disk, using spectroscopic parallax of the X-ray thermal component.
However, an accurate application of this technique is fraught with
difficulties. Monitoring programs that track the evolution of the thermal and
power-law components in the X-ray spectrum provide new insights into modes of
energy flow and the formation of relativistic jets.
