I have always wanted to make "crazy crayons" using my old crayon pieces as a kid...my mom never got around to doing it (I think she thought the MANY instances of melted crayons in the car was enough for her..haha!)
I still want to. In fact, it is high on my list of things I want to make and tuck away for gifts. I ran across this site that sells silicone molds for making crayons, among many other things...in the shape of letters or numbers. Here is another link with recipes of different things you could use your silicone molds for...I think it's pretty ingenious. You could also use it to mold butter, chocolate, water (for ice) and a whole lot more. I think it would be so cute to use these individual number trays to make "crazy crayons" for a party favor...and for the ice cubes etc.