  We present an analysis of the globular cluster systems of 28 elliptical
galaxies using archival WFPC2 images in the V and I-bands. The V-I color
distributions of at least 50% of the galaxies appear to be bimodal {\it at the
present level of photometric accuracy}. We argue that this is indicative of
multiple epochs of cluster formation early in the history of these galaxies,
possibly due to mergers. We also present the first evidence of bimodality in
low luminosity galaxies and discuss its implication on formation scenarios. The
mean color of the 28 cluster systems studied by us is V-I = 1.04$\pm$0.04
(0.01) mag corresponding to a mean metallicity of Fe/H = -1.0$\pm$0.19 (0.04).
We find that the turnover magnitudes of the globular cluster luminosity
functions (GCLF) of our sample are in excellent agreement with the distance
measurements using other methods and conclude that the accuracy of the GCLF is
at least as good as the surface brightness fluctuation method. The absolute
magnitude of the turnover luminosity of the GCLF is M$_V^0$ = -7.41 (0.03) in V
and M$_I^0$ = -8.46 (0.03) in I. The mean local specific frequency of our
sample of elliptical galaxies within the WFPC2 field-of-view is 2.4$\pm$1.8
(0.4), considerably higher than the 1.0$\pm$0.6 (0.1) derived for a comparable
sample of S0s in a similar analysis. It shows no obvious correlation with
metallicity, host galaxy mass or membership in a galaxy cluster. The median
size of clusters in all galaxies appears to be remarkably constant at $\sim$2.4
pc. We suggest that in the future it might be possible to use the sizes of
clusters in the inner regions of galaxies as a simple geometrical distance
indicator.
