another suggestion nobody's hit on:

subclass DBI::MySQL to handle the connection phase for you. that way, other developers wouldn't necessarily need to know the password, if that's the concern.

this solution also makes it easier to handle any encryption you'll probably want to do later on, and requires one change in one place, not tons of changes all over.

developer code would look more like this:

#!/usr/bin/perl

use MyDBI;

my $dbh = MyDBI->db_logon();       # defined in MyDBI, obviously
my $sth = $dbh->prepare( 'SELECT * FROM foo ');
[download]

and so on.