Ask HN: Is there a tool to "find startups like ____"?

Quora is usually a good place for finding stuff like this. Usually someone has already asked a question for startups similar to X (assuming X is popular enough), and one of the answers is usually rather comprehensive.

For example: http://www.quora.com/What-startups-are-working-on-Uber-for-X?

Not trying to troll but Google usually works just fine for that kind of thing. However I do accept that it would be nice to have a utility designed specifically for that kind of question.

http://heisenberg.ziraffe.in/

Product Hunt?

Mattermark