use theme functions

I just wanted to suggest you to use more theme functions :
this way, we could use phptemplate to modify the html rendering if we want, without having to tweak the module.

For example, for the menu rendering, I wanted to show their title, instead of 'Primary Links' or 'Secondary Links'.

So I had to go in the _site_map_menus() function in sitemap.module, and replace

if($mid == 'primary-links'){
  $output .= '<h3>Menu principal</h3>';
}
if($mid == 'secondary-links'){
  $output .= '<h3>Menu secondaire</h3>';
}

by

$output .= '<h3>'. $menu['title'] .'</h3>';

If it has been a theme function, i would just have to go in my template.php and redeclare the function with phptemplate (or my theme name) to do this.

Is it possible, or am I totally out ?

thanks ;)