Someone says: Crayon hot rocks: If you have not done this yet, you need to. Simply warm up the rocks in the oven (I did 220 for 10 minutes), then put them on a stack of newspapers (or something else you don't care if it gets crayon in it) and let the little ones go to town. Just remind them it is hot. I have done it with 2 1/2 year olds with no problem. My little lady often brings in rocks for me to "cook" so she can paint them
Borax snowflakes - If you have Borax at home, you SO need to do this with the kids. Do it after dinner, and by breakfast the kids will be amazed at what has happened! We have 8 snowflakes hanging in our window just a-sparkling away!