Twisted Sifter has a great gallery of snowflake and ice crystal electron microscope photos. At this level of magnification, the ice looks like metal that has been machined by space aliens.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects