This snippet will allow you to set custom excerpt lengths in your excerpt tag in your WordPress template.

Instructions
Add this code to your functions.php file.

<?php
   function excerpt($limit) {
      $excerpt = explode(' ', get_the_excerpt(), $limit);
      if (count($excerpt)>=$limit) {
         array_pop($excerpt);
         $excerpt = implode(" ",$excerpt).'...';
      } else {
         $excerpt = implode(" ",$excerpt);
      } 
      $excerpt = preg_replace('`\[[^\]]*\]`','',$excerpt);
      return $excerpt;
   }
   function content($limit) {
      $content = explode(' ', get_the_content(), $limit);
      if (count($content)>=$limit) {
         array_pop($content);
         $content = implode(" ",$content).'...';
      } else {
         $content = implode(" ",$content);
      } 
      $content = preg_replace('/\[.+\]/','', $content);
      $content = apply_filters('the_content', $content); 
      $content = str_replace(']]>', ']]&gt;', $content);
      return $content;
   }
?>

And then use this syntax to invoke your custom excerpt length in your template:

<?php echo excerpt(35); ?>