I want to configure phpMyAdmin to be able to accept one of several different user account logins. Each user would be allocated a specific database and only have access to that.<
If you want to add a different host with user and password defined, you can do it adding the next lines on the config.inc.php
the first parameter auth_type element sets as cookie
$cfg['Servers'][$i]['auth_type'] = 'cookie';
and the second conection changes as config (increment the i variable)
$i++;
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['user'] = 'user';
$cfg['Servers'][$i]['password'] = 'password';
$cfg['Servers'][$i]['host'] = 'anotherhost';
$cfg['Servers'][$i]['connect_type'] = 'tcp';