Sometimes I have wanted to make some simple changes to a drupal theme based on the current root path. The sections module does this, but I wanted a simpler way of changing elements in the CSS based on the current root path.
function _phptemplate_variables($hook, $vars = array()) {
switch ($hook) {
case 'page':
if (module_exists('path')) {
$alias = drupal_get_path_alias($_GET['q']);
if ($alias != $_GET['q']) {
foreach (explode('/', $alias) as $path_part) {
$classes[] = $path_part;
}
}