  Only BL Lac objects have been detected as extragalactic sources of very high
energy (E > 300 GeV) gamma rays. Using the Whipple Observatory Gamma-ray
Telescope, we have attempted to detect more BL Lacs using three approaches.
First, we have conducted surveys of nearby BL Lacs, which led to the detections
of Mrk 501 and 1ES 2344+514. Second, we have observed X-ray bright BL Lacs when
the RXTE All-Sky Monitor identifies high state X-ray emission in an object, in
order to efficiently detect extended high emission states. Third, we have
conducted rapid observations of several BL Lacs and QSOs located close together
in the sky to search for very high flux, short time-scale flare states such as
have been seen from Mrk 421. We will present the results of a survey using the
third observational technique.
