Use multiple routing files.

routing.yml

## Default rules ===============================================================
homepage:
  url:   /
  param:
    module:    home
    action:    index
    sf_format: html

<?php foreach(glob(dirname(__FILE__).DIRECTORY_SEPARATOR.'routing'.DIRECTORY_SEPARATOR.'*.yml') as $yml){ require($yml); echo "\n"; } ?>

I think it's better to use :

<?php foreach(glob(dirname(__FILE__).DIRECTORY_SEPARATOR.'routing'.DIRECTORY_SEPARATOR.'*.yml') as $yml){ require($yml); echo "\n"; }?>

require is faster than require_once and echo "\n"; is there to enforce new line :)

Your tips on "\n" is awesome, I had some prob which forced me to make the new line into my separate routing files ;)