Did you know tumblr had a Q&A feature?
I had no idea, but apparently they do. From the tumblr faq:
Create a new Text, Photo, Link, Audio, or Video post and end a text box with a question mark (?). Then, click the “Let people answer this” box that appears on the right side of the page. Question & Answer is not supported in Quote or Chat posts.
You cannot edit an existing post to make it a Question & Answer post. A post must be designated for a Question & Answer when it is first created.
Answers are disabled on a Question & Answer post after seven days.
Did you know?