How do I log out?

Assuming you have not disabled the navigation menu under the title bar via your User Settings, the very first link in the list will say "Log Myself out". Click that to log out.

Similarly, if you have the Leftovers Nodelet enabled via your Nodelet Settings, the link is there.

If you're reading this node and you want to log out now, then here's the link for you convenience: Log out now.

Of course, none of this makes sense unless you are logged in.