functions-custom-excerpt.php

<?php
/** 
 * custom excerpt length for WordPress posts
 * call the excerpt in your theme file with 'echo excerpt(25)'
 * change the number to whatever amount of words you want to show
 */
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;
}
?>