  We present ground-based optical observations of the September 2009 and
January 2010 transits of HD 80606b. Based on 3 partial light curves of the
September 2009 event, we derive a midtransit time of T_c [HJD] = 2455099.196 +-
0.026, which is about 1 sigma away from the previously predicted time. We
observed the January 2010 event from 9 different locations, with most phases of
the transit being observed by at least 3 different teams. We determine a
midtransit time of T_c [HJD] = 2455210.6502 +- 0.0064, which is within 1.3
sigma of the time derived from a Spitzer observation of the same event.
