Quora, is a question-and-answer site where questions are asked, answered and organized by its community of users. 

Quora connects you to everything you want to know about.

Users can collaborate by editing questions and suggesting edits to other users' answers.

Link: quora.com

I don't know of any other site, but I haven't been looking for it either. 

Intersting profile photo you have, it reminds me of Bulgakov.