I'm with you, to an extent. Right this minute, I'm having a discussion with my partner about secondary pay per click partners.
You asked for 'pay for inclusion' engines but referenced Overture. So I thought I might talk about the pay per click field. Pay for inclusion engines would include Inktomi, Teoma and Fast. But that's a whole other can of worms.
I'm interested in FindWhat, Ah-Ha, Search123, and Kanoodle, myself.
But let me see if I can help you.
Here are some Overture Partners:
Here are some Google AdWords Partners:
New York Times
Sympatico - CA
Yahoo - Japan
Here is a more thorough listing from this thread:
Dogpile* Search results 31-35 on page 1
Canada.com* Search results 21-25 on page 1
Infospace* Search results 21-25 on page 1
NBCI* Search results 21-25 on page 1
SearchGalore After searchgalore paid results
CNET 6 thu 8th spots from "The Web" search and first 5 results on "see more Search partners results"
Mamma Random listings in search results
Metacrawler Random listings in search results
Search.com 6 thu 8th spots from "Search partners" search and first 5 results on "see more Search partners results"
Excite.com Listings 17-20 in regular search results
Webcrawler Listings 17-20 in regular search results
United Online's NetZero and Juno sites.
Infospace (Dogpile and Metacrawler)
This is just the tip of the iceberg for all of these engines. This question is ripe for a relationship chart. If anyone else has any additional partnerships to add to this list I would love to see 'em.