Four Close Approaches in Next Ten Months and still counting!  See Interactive Orbits at following links:


August, 2011 (.06 AU from earth)  45P/Honda-Mrkos-Pajdušáková 
            http://ssd.jpl.nasa.gov/sbdb.cgi?ID=c00045_0;orb=1;cov=0;log=0;cad=0#orb

October, 2011 (.23 AU from earth)  C/2010 X1 (Elenin)  
            http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=P%2F2010%20X1;orb=1;cov=0;log=0;cad=0#orb

January, 2012 (.05 AU from earth)  P/2006 T1 (Levy)  
            http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=P%2F2006%20T1;orb=1;cov=0;log=0;cad=0#orb

November 9th, 2011  (0.85 Lunar distances)  400 meter Asteroid 2005 YU55
Although classified as a potentially hazardous object, 2005 YU55 poses no threat of an Earth collision over at least the next 100 years. However, this will be the closest approach to date by an object this large that we know about in advance and an event of this type will not happen again until 2028
            http://neo.jpl.nasa.gov/news/news171.html