We present an analysis of over 2200 V images taken on 14 nights at the Mt .
Laguna 1 m telescope of the open cluster M67 .
Our observations overlap but extend beyond the field analyzed by Gilliland et al .
( 1991 ) , and complement data recently published by van den Berg et al .
( 2002 ) and Stassun et al .
( 2002 ) .
We show variability in the light curves of all 4 of the known W UMa variables on timescales ranging from a day to decades ( for AH Cnc ) .
We have modeled the light curve of AH Cnc , and the total eclipses allow us to determine q = 0.16 ^ { +0.03 } _ { -0.02 } and i = 86 \arcdeg ^ { +4 } _ { -8 } .
The position of this system near the turnoff of M67 makes it useful for constraining the turnoff mass for the cluster .
We have also detected two unusual features in the light curve of AH Cnc that may be caused by prominences .
We have also monitored cluster blue stragglers for variability , and we present evidence hinting at low level variations in the stragglers S752 , S968 , and S1263 , and we place limits on the variability of a number of other cluster blue stragglers .
Finally , we provide photometry of the sub-subgiant branch star S1063 showing variability on timescales similar to the orbital period , while the “ red straggler ” S1040 shows evidence of an unexplained drop in brightness at phases corresponding to the passage of the white dwarf in front of the giant .