A colleague and I were just talking the other day about the old saying that "no two snowflakes are alike." He pointed out that the same could be said for grains of sand on the beach, but that no one (save a materials physicist) would point that out. How appropriate that the following article came up in my news feed today:

LiveScience.com - Scientist: Maybe Two Snowflakes are Alike:

"'How likely is it that two snowflakes are alike? Very 
likely if we define alike to mean that we would have trouble 
distinguishing them under a microscope and if we include the 
crystals that hardly develop beyond the prism stage—that is, 
the smallest snow crystals,' Nelson said."