Changing your Wordpress Admin Username
Changing your Wordpress username to something other than admin is reportedly a good way to help stave off brute force or dictionary attacks, where the hacker already knows your username and is only trying for your password.
It can be done by opening up PHPmyAdmin, going to the users table, and locating the user_login column. If you change that, your wordpress username will change.
Note - you should backup your database before attempting this, just in case. Do not attempt this unless you are confident that you know what you are doing - if in doubt, get someone to do it for you.