FYI I was playing around with custom google search engines and created a recipe search that indexes some of my favorite paleo recipes sites. One of those things that I might as well share since I put the time into it and I'll keep updating it as I come across more sites..
Paleo Recipes Search Engine
Not sure if it tells non-admin users which sites are included, but you can get a pretty good idea by looking at the results.
I threw that one up with a few others I worked on at: