Noah's joke (made up by himself):

If you are having a fit and get sent to bed, what kind of mattress do you need?

A Temper-pedic!

I thought that was pretty good from an eight year old.  As I was once told by a six year old "There are two kinds of jokes.  The kind that make sense and the kind that don't."  Usually from kids under 10 I get ones made up that fall into the second category!