  The first transiting extrasolar planet, orbiting HD209458, was a Doppler
wobble planet before its transits were discovered with a 10 cm CCD camera.
Wide-angle CCD cameras, by monitoring in parallel the light curves of tens of
thousands of stars, should find hot Jupiter transits much faster than the
Doppler wobble method. The discovery rate could easily rise by a factor 10. The
sky holds perhaps 1000 hot Jupiters transiting stars brighter than V=13. These
are bright enough for follow-up radial velocity studies to measure planet
masses to go along with the radii from the transit light curves. I derive
scaling laws for the discovery potential of ground-based transit searches, and
use these to assess over two dozen planetary transit surveys currently
underway. The main challenge lies in calibrating small systematic errors that
limit the accuracy of CCD photometry at milli-magnitude levels. Promising
transit candidates have been reported by several groups, and many more are sure
to follow.
