Can a different template be appliied to certain pages?

You can create different custom Page templates and apply them on an ad-hoc basis.

I have qurstion : how can apply a custom theme for a single page? the filter template is not working .. I’m attaching the code below

<?php
/*
Plugin Name: ThemeSelect_OOPS_NEW
Plugin URI:
Description: This will allow admin chose a theme for a new page
Version: 0.0.1
Author:
Author URI:
License: GPL
*/
class ThemeSelect
{
	function ThemeSelect()
	{
		add_action('admin_menu',array(&$this,'add_theme_box'));
		add_action('save_post',array(&$this,'save_theme'));
		add_filter('template', array(&$this,'get_post_template'));
		add_filter('stylesheet', array(&$this,'get_post_stylesheet'));
	}
	function add_theme_box() /* Adds a custom field to set theme */
	{
	if( function_exists( 'add_meta_box' ))
	{
		add_meta_box( 'theme', 'Select Theme',array(&$this, 'show_theme_selector'),'page','normal', 'high');
	}
	}
	function show_theme_selector($post)  /* Loads the select menu for the theme selector*/
	{
		$themes=get_themes();
		$postid=$post->ID;
		if(get_post_meta($postid,'theme',true))
		$default_theme=get_post_meta($postid,'theme',true);
		echo "<select name=\"thm\">";
		foreach($themes as $theme)
		{ ?>
			<option value="<?php echo $theme['Name']; ?>" <?php if($default_theme==$theme['Name']) echo "selected=\"selected\""; ?>> <?php echo $theme['Title']; ?> </option>
	<?php   }
		echo "</select>";
	}
	function save_theme($postid)
	{
		if(isset($_POST['thm']))
		{
			$themedata = $_POST['thm'];
			//if(get_post_meta($postid,'theme', true)=="")
			//{
			//	add_post_meta($postid,'theme',$themedata);
			//}
		//	else
		//	{
			update_post_meta($postid,'theme',$themedata);
		//	}
	}
}

function get_post_template($template='')
{
	global $post;
	$sel_theme = get_post_meta($post->ID, 'theme', true);
	if(!empty($sel_theme))
	{
		$theme=get_theme($sel_theme);
		$template = stripslashes($theme['Template']);
		//$template=get_theme_root()."/{$template}/page.php";
	}
	return $template;
}

 function get_post_stylesheet($stylesheet='')
 {
 	global $post;
 	$sel_theme = get_post_meta($post->ID, 'theme', true);
 	if(!empty($sel_theme))
 	{
 		$theme=get_theme($sel_theme);
 		$stylesheet = stripslashes($theme['Stylesheet']);
 	}
 	return $stylesheet;
 }
}
$theme_select=new ThemeSelect();
?>

Any idea?

to:webmaster887
If you aren’t use this plugin, you can styling your template be yourself..
For example: u’r make a different header and then put this on your single.php with this code:
<?php include (TEMPLATEPATH . '/different-header.php'); ?>