  We describe the results of a search for transit-like events caused by giant
planets occulting stars in the old, metal-rich open cluster NGC 6791 based on
BVI-colour photometry from eight nights of observations with the 2.54m Nordic
Optical Telescope. To extract the light curves we have used both PSF photometry
(DAOPHOT) and the difference imaging technique (ISIS). We have re-analyzed
observations from earlier campaigns to search for multiple transits, determine
periods of long-period variables, and detect eclipsing binaries. We confirm 20
known variables and have discovered 22 new low-amplitude variables with
amplitudes in the range 7--40 mmag and periods 1--16 days. We have found the
primary and secondary eclipses of two eclipsing binaries based on the new and
older photometric campaigns. The search for transits-like events has turned up
a few single-transit candidates. The transit depths are 10 mmag in both the V
and I filters over periods of 1.0--2.5 hours, but future observations are
required to see whether identical transit-like events recur in these same
stars.
