Whenever I have leftover batting, I make a few more circles for my QAYG project. Here's a link to pics from someone on the boards WIP of the same....
http://www.quiltingboard.com/t-110832-1.htm
I probably have about 80 circles in a box right now. I'll need a few more to make a bed quilt. It's a great way to use up scraps of everything, although I do use muslin for the one side of the circle just to tone it down a bit and unify it.