Aaron's list is top secret because it's part of the SEO Book.
I have done extensive research on static-URL search-engine-spiderable directories (either free or paid - not including niche, speciality or very tightly focused directories) that don't
require a reciprocal link and will provide a regular html link back to your site.
I can say without a doubt there aren't many on the net. My list is hovering somewhere around 100. And yes, my list is top secret too!
