Asu -- Great minds think alike. A couple of your suggestions were in my original pool of ideas. Just because they didn't make the first rounds of elimination doesn't mean they aren't still there. We can still go back with fresh eyes later, and maybe will.

tricksi -- Awesome selling point about the three stones and the three kids! I might have to use that little bit of psychology. Oh, I can hear the kids in my head fighting over who is the bigger center stone...