Sorry, I hope this is not too off-topic, but I couldn't think of any other place to ask.

One search engine was specialised on finding people. The special feature was that people could "adopt" the result page for themselves and add more specific information. So it was also a kind of Wiki, I guess.

The other one also allowed people to add meta data to the search result, in theory a kind of semantic web could emerge.

Both are fairly recent startups, I think. Don't know why I can't find them in my bookmarks anymore :-(