This fun HOWTO from Caltech shows you how to grow your own snowflakes at home with a coke bottle, a couple of styrofoam cups, some dry ice, and a few other common household items.
I find the effect of electric fields on growing ice crystals particularly fascinating.
Happy holidays!
Check it out: Ice lightning! http://www.its.caltech.edu/~atomic/snowcrystals/electric/highv1.jpg
Love the electric holiday theme!