Is something similar to what is found at experts exchange available?

[coffeeam]

What I would like to do, is have a specific "question" board where a user can post a question, and then when they get the correct answer to something, flag a particular post as the accepted answer, or if multiple answers are given, assisted answer flags, and then can lock the thread.

Example (scroll down, if answers are not showing, clear browser cookies):

http://www.experts-exchange.com/Operating_Systems/Windows_Server_2003/Q_21730995.html

Is there anything remotely similar to this available for vbulletin?

[kafi]

I would also even pay for this .-)