I installed the LAMP + phpmyadmin combo yesterday on my Ubuntu Intrepid machine for hosting a local website.
But later I realized that the phpmyadmin page, though password protected, was visible throughout my local network! So, to disable remote access to phpmyadmin , add the following code to the end of your /etc/apache2/apache2.conf file ..
# Disabling phpmyadmin for remote access
Deny from all
Allow from localhost