Remembrance Day

Google Australia's homepage

Google puts a poppy flower on their UK, Canada, and Australia's homepages to commemorate the fallen of the First World War and all wars and armed conflicts since then.

Source: http://www.google.com/images/icons/hpcg/poppy_red_42.gif

a blue conrflower on Google France's homepage:

Source: http://www.google.fr/images/icons/hpcg/cornflower-bluepurple_42.png

and carnation flower on Google Turkey's homepage:

Source: http://www.google.com.tr/images/icons/hpcg/carnation-r42.gif