After entering the wrong MySQL password I receive the message “ERROR 1129 (HY000): Host is blocked because of many connection errors; unblock with ‘mysqladmin flush-hosts'” and can no longer log in, what can I do?

Connect to MySQL from another host and run the SQL command “flush hosts”. If you have phpMyAdmin installed on the MySQL server you can also connect from your current host, the connection will be seen as coming from localhost.