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 \pm 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 \pm 0.0064 , which is within 1.3 \sigma of the time derived from a Spitzer  observation of the same event .