clumping vs. random

Hi Kristen,
Are you are just interested in "clumpiness" in time, or "clumpiness"
in space and time? Are your sites far enough apart that the
environmental process
you are looking at can be assumed independent? If you have the spatial
coordinates, even approximate, you could calculate Moran's I for the
whole data
set which would give you a rough estimate of the tendency for 1's and
0's 
to cluster together, on average. But that won't tell you a lot about the
behavior
of the process. A little more information about the study would help to
give you a more specific answer.

Nicholas