gistfile1.php

//filter the <p> tags from the images and iFrame
function filter_ptags_on_images($content) {
	$content = preg_replace('/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(<\/a>)?\s*<\/p>/iU', '\1\2\3', $content);
	return preg_replace('/<p>\s*(<span .*>)?\s*(<iframe .*>*.<\/iframe>)\s*(<\/span>)?\s*<\/p>/iU', '\1\2\3', $content);
}
add_filter('the_content', 'filter_ptags_on_images');