Turns out that there are 500 boxes of all Cheerios varieties sold per minute in fiscal year 2010.  Of the 500 sold, Honey Nut Cheerios (my personal favorite) claims the top spot followed by regular Cheerios.  Those 2 cereals hold the #1 and #2 spot among top-selling cereals in the US.  Cheerios is a brand from General Mills (GIS), the 6th largest food company in the world.

Source: Bloomberg Businessweek

Picture via bpende