how to configure phpMyAdmin on a cobalt 4i to make it availabe to all websites hosted on it?

Basically go to phpwizard.net read the advanced authentication documentation and you will be good to go.

There is also a very good tutorial on devshed.com

here is an excerpt:

Using Advanced Authentication:

phpMyAdmin needs a stduser that has only the SELECT privilege on the mysql.user (all columns except "Password"), mysql.db (all columns) & mysql.tables_priv (all columns except "Grantor" & "Timestamp") tables.
You must specify the details for the stduser in the config.inc.php3 file under the $cfgServers[n]['stduser'] & $cfgServers[n]['stdpass'] settings.
To create the control account (<stduser> and <stdpass> have to be replaced by your own values, of course):
GRANT USAGE ON mysql.* TO '<stduser>'@'localhost' IDENTIFIED BY '<stdpass>';
GRANT SELECT (Host, User, Select_priv, Insert_priv, Update_priv, Delete_priv, Create_priv, Drop_priv, Reload_priv, Shutdown_priv, Process_priv, File_priv, Grant_priv, References_priv, Index_priv, Alter_priv) ON mysql.user TO '<stduser>'@'localhost';
GRANT SELECT ON mysql.db TO '<stduser>'@'localhost';
GRANT SELECT (Host, Db, User, Table_name, Table_priv, Column_priv) ON mysql.tables_priv TO '<stduser>'@'localhost';
... and if you want to use the bookmark feature:
GRANT SELECT, INSERT, DELETE ON <bookmark_db>.<bookmark_table> TO '<stduser>'@'localhost';


Then each of the true users should be granted of a set of privileges on a set of perticular databases but shouldn't have any global privileges. For example, to grant the user real_user with all privileges on the database user_base:
GRANT ALL PRIVILEGES ON user_base TO 'real_user'@localhost IDENTIFIED BY 'real_password';
What the user may now do is controlled entirely by the MySQL user management system.