I got sick of picking up broken crayons from all around my sons "art station" so I took them all and melted them into a huge "mega crayon" in an old deodorant bottle. So far, so good, he seems to like it.
The whole project was super simple, just melt crayons and pour them into the deodorant container. I did spray the inside of the container with "mold release" (which always makes me think of mold, like bread mold, RELEASE! you molds. anyway...) and the site where I got the idea from suggested slipping a drinking straw over the threaded rod in the container to prevent the crayon from binding to it...so I did that too. Worked beautifully.
I posted a step by step, including a link to the website where I got most of my info, on my blog.