I don't really have an organized presentation ready, but I made some
slides!
http://docs.google.com/present/view?id=0AWauxz6V47pGZGQzdnEzNzVfMGNtdjV0c2Rj&hl=en
I had a hard time getting google to use the font sizes I wanted, so
some of the typography is a mess.
The example code is lifted from Practical Common Lisp, chapter three.
It does the best job I've seen in encapsulating what is special about
Lisp in a single simple example.
Anyway hope to see y'all there.
Matt