Finding variables available in preprocess node or node.tpl.php from cck fields
Yes, you can do something like this in a custom module:

function YOURMODULE_preprocess_node(&amp;$vars) {
  drupal_set_message('&lt;pre&gt;' . print_r($vars, true) . '&lt;/pre&gt;');
}


or this in your theme's template.php file:

function YOURTHEME_preprocess_node(&amp;$vars) {
  drupal_set_message('&lt;pre&gt;' . print_r($vars, true) . '&lt;/pre&gt;');
}


If that's too much information, you can get just the variable names with:

 foreach ($vars as $name =&gt; $value) {
   drupal_set_message($name);
 }


instead of print_r()ing the entire array.