If you think discussions could provide the best source of information for you then omgili.com is the answer. Omgili is a search engine specialise in indexing and searching through discussion boards or forums.

For an example if I want to search about Why my Google webmaster sitemap are in pending status, I just need to type in the search query (link) and got a list of conversation about it.

How about Busby SEO Test ?
Well, when I try to search about Busby SEO Test, only few quality discussion about it. Most of Omgili.com indexed page are a thread with signature related to the second Busby SEO Contest.