I have an application I run under mod_perl where doing the configuration involves some fairly heavy lifting. I reduce the configuration into a hashref, and then use the Storable module to stick the data in a file. I find the lock_nstore and lock_retrieve functions you can import from Storable a very hady and compact way to do this. When I load the Apache module, I retrieve the file and thaw it. Thereafter I track the modification time to see if I need to load a new copy of the data structure.

Lately I've taken to just writing short perl scripts like

use Storable qw/lock_nstore/;

my $cfg = {
  ## configuration data here
};

lock_nstore($cfg => '/some/file/name/here');
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And doing a quick edit of the data structure and rerunning them to change the server configuration.

Of course, avoid doing this for truly massive (> 10,000 items) data structures, as your server process memory consumption will just eat you alive.