Q:

Should OP be able to close their own question? 

Should an asker have the ability to close his own question at will, regardless of their reputation?  I am not saying that they should be able to delete it, nothing of the sort.  What I mean is that OP should be allowed to close his own question if he believes it is a duplicate, or does not fall within SO guidelines.  To me, this makes sense, since no person would want their question to be flagged, so I cannot see why such a feature would be abused. 
What would be the pros and cons of implementing such a feature? 

A:

Users are given the ability to vote to close their own questions at 250 reputation, when it is presumed they have been on the site for a while and thus have an idea of how closing questions work and how to use their votes accordingly. 
The only con I can think of is if someone tries to vote to reopen all of their closed questions when they really ought to stay closed (or tries to close all their perfectly acceptable questions).  But I think reviewers will handle that just fine.