Your "User Tutle" changes once you hit a certain number of posts. I think that once you hit 75 posts, you are promoted from "Earning My Ears" to "Mouseketeer".
You can also change this title to something else by going into User CP (top left of this board, in the dark blue stripe) and clicking on the "Edit Profile link. In the Customer User Title Box, you can enter your new tag.
The tag fairy may also visit you and add another line to your User Title.