I definitely try and feedback if the answers didnt apply correctly to me
i also like to make sure i award the person that answered my question by selecting it
personally I'm not sure on the merit of allowing anonymous posting, i kind of think that but raising the bar just slightly by requiring registration means that users are already more motivated to come back as they have taken the few moments in the first place to register or sign in with facebook.
i have to encourage people to use the up and down vote buttons as well even if the question doesnt directly apply to you, if you know its a good/correct answer, then upvote it
if its a bad/wrong answer then downvote it