makeshift67

Here, i found this on google.

<?php
//edit below for categories you want excluded
$exclude = array("Featured", "Uncategorized");
//how do you want the list separated? just a space is okay
$separator = " | ";
//don't edit below here!
$new_the_category = '';
foreach((get_the_category()) as $category){
	if (!in_array($category->cat_name, $exclude)){
		$new_the_category .= '<a href="'.get_bloginfo(url).'/'.get_option('category_base').'/'.$category->slug.'">'.$category->name.'</a>'.$separator;
	}
}
echo substr($new_the_category, 0, strrpos($new_the_category, $separator));
?>

hope it helps.