I caught the link while surfing in the last night. It provides the feature do follow blog search and the interesting thing is "It is from google" Here is the link http://www.google.com/coop/cse?cx=010363265520675485990:xjmxcyokkls
That's a normal custom search engine. And it's not from Google. Both yahoo and google allow webmasters to create their own search engines that will only search within pre-defined set of websites / pages. Don't believe me? You can see the list of such dofollow search engines, just click on 'more results or second' page and you will see google custom search screen.
Thanks for another google cse. These are as good as long as they are maintained. Unfortunately I've never found one to be better than 50% dofollow. Also check the sites with nodofollow plugin in firefox.
There is a really good dofollow blog finder in my links bellow that is maintained and about 90% of the blogs are currently dofollow. The only reason they are not all dofollow is because webmasters turn the dofollow plugin off due to spammers so please don't spam!