To change your "Display Name", click on your x500 username in the upper right-hand corner of the UThink/Movable Type blog backend. (See circled area in image below)

Once on the "Author Profile" screen, input the name you want to display (your first and last name would be fine) on the website in the "Display Name" field.

Save the form and the next time the site is rebuilt (when someone posts a new entry/comment), your name will show rather than your x500 id.

Everyone should do this if your name is now showing up. It will help in keeping track of who's writing what!