functions.php

<?php 
/**
 * /iPhone webapp & Favicon
 */
if (!function_exists('xc1_favicon')) {
	function xc1_favicon() {
		if (file_exists ( CHILD_THEME_IMAGES_PATH . 'xc1-iphone.png' ))
			$apple_icon = CHILD_THEME_IMAGES_URI . 'xc1-iphone.png';
		else
			$apple_icon = XC1_THEME_IMAGES_URI . 'xc1-iphone.png';
		
		if (file_exists ( CHILD_THEME_IMAGES_PATH . 'xc1-iphone-startup.png' ))
			$apple_startup = CHILD_THEME_IMAGES_URI . 'xc1-iphone-startup.png';
		else
			$apple_startup = XC1_THEME_IMAGES_URI . 'xc1-iphone-startup.png';
		
		if (file_exists ( CHILD_THEME_IMAGES_PATH . 'xc1-favicon.png' )) 
			$favicon_icon = CHILD_THEME_IMAGES_URI . 'xc1-favicon.png';
		else
			$favicon_icon = XC1_THEME_IMAGES_URI . 'xc1-favicon.png';
		
		if (get_option ( 'show_avatars' )) {
			echo "<link rel=\"apple-touch-icon-precomposed\" href=\"$apple_icon\" />\n";
			echo "<link rel=\"apple-touch-startup-image\" href=\"$apple_startup\" />\n";
			echo "<link rel=\"shortcut icon\" type=\"image/png\" href=\"$favicon_icon\" />\n";
			
		}
	}
}

/**
* Check to see if this page will paginate
* 
* @return boolean
*/
function will_paginate() 
{
	global $wp_query;
  
	if ( !is_singular() )  {
		$max_num_pages = $wp_query->max_num_pages;
    
		if ( $max_num_pages > 1 ) {
      		return true;
    	}
  	}
  	
  	return false;
}

rewrites.php

<?php
class XC1_Mobile_Rewrites extends XC1_Mobile {
	public function __construct($mobile) {
		$this->mobile = $mobile;
	}
	
	/*
	 * From .html on pages (http://wordpress.org/extend/plugins/html-on-pages/) by IntroSites
	 */
	public function html_page_permalink() {
		global $wp_rewrite;
		if ( !strpos($wp_rewrite->get_page_permastruct(), '.html')) {
			$wp_rewrite->page_structure = $wp_rewrite->page_structure . '.html';
		}
	}
	
	public function no_page_slash($string, $type){
		global $wp_rewrite;
		if ($wp_rewrite->using_permalinks() && $wp_rewrite->use_trailing_slashes == true && $type == 'page') {
			return untrailingslashit($string);
		} else {
		   return $string;
		}
	}
	
	public function active() {
		global $wp_rewrite;
		if ( !strpos($wp_rewrite->get_page_permastruct(), '.html')) {
			$wp_rewrite->page_structure = $wp_rewrite->page_structure . '.html';
	 	}
	 	
	  	$wp_rewrite->flush_rules();
	}	
	
	public function deactive() {
		global $wp_rewrite;
		$wp_rewrite->page_structure = str_replace(".html","",$wp_rewrite->page_structure);
		$wp_rewrite->flush_rules();
	}

  	// Remember to flush_rules() when adding rules
  	public function flushRules() {
  		global $wp_rewrite;
  	
    	$wp_rewrite->flush_rules();
  	}

}

xc1-mobile.php

<?php 
/*
Plugin Name: XC1 Mobile
Plugin URI: 
Description: XC1 made mobile compatible
Version: 0.9
Author: Anders Hassis
Author URI: http://hassis.com
*/

if (!defined('WP_SITEURL')) {
	define('WP_SITEURL', get_option('siteurl'));
}

if (!defined('WP_HOME')) {
	define('WP_HOME', get_option('home'));
}

require_once('includes/functions.php');
require_once('includes/rewrites.php');

class XC1_Mobile {
	private $themeChildPath;
	private $themeChildURI;
	
	private $themeMobileName;
	private $themeMobilePath;
	private $themeMobileURI;
	
	private $desiredView;
	
	private $pluginURI;
	private $pluginPath;
	
	public $Rewrites;
	
	public function __construct() {
		$this->Rewrites = new XC1_Mobile_Rewrites($this);
		
		// Check if user switches layout
		if (isset($_GET['xc1-layout'])) {
			switch ($_GET['xc1-layout']) {
				case 'mobile':
					$this->setLayout('mobile');
					break;
				default:
					$this->setLayout('default');
					break;
			}
		}
		
    	add_filter('init', array(&$this->Rewrites, 'flushRules') );    			
    	
		if (isset($_COOKIE['xc1-layout'])) {
			if ($_COOKIE['xc1-layout'] == 'mobile') {
				$this->desiredView = 'mobile';
			} else {
				$this->desiredView = 'default';
			}	
		} else {
			if ( self::isMobile() ) {
				$this->desiredView = 'mobile';
			} else {
				$this->desiredView = 'default';
			}
		}
		
		if ($this->desiredView == 'mobile') {
			$this->init();
		}
	} 
	
	private function init() {
		// Make sure we have a trailing .html on pages 
		add_action('init', array(&$this->Rewrites, 'html_page_permalink'), -1);
		register_activation_hook(__FILE__, array(&$this->Rewrites, 'active'), '');
		register_deactivation_hook(__FILE__, array(&$this->Rewrites, 'deactive'), '');
		add_filter('user_trailingslashit', array(&$this->Rewrites, 'no_page_slash'), '',66,2);
		
		// Define the URI to plugin
    	$this->pluginURI = WP_PLUGIN_URL . "/" . basename(dirname(__FILE__)) . "/";
    	$this->pluginPath = WP_PLUGIN_DIR . "/" . basename(dirname(__FILE__)) . "/";
    	
    	// Find our child/parent theme
		$this->themeChildPath = get_stylesheet_directory();
		$this->themeChildURI = get_stylesheet_directory_uri();

		// Hook into it and add our trailing -mobile
		$this->themeMobileName = get_stylesheet() . '-mobile';
		$this->themeMobilePath = $this->themeChildPath . '-mobile';
		$this->themeChildURI = $this->themeChildURI . '-mobile';
		
		// Make sure the mobile theme exists
		if (!is_dir($this->themeMobilePath))
			return;

		// Constants (XC1-style)
		$this->constants();

		// Buckle up!
		if ( !is_admin() ) { 
			add_filter('stylesheet', array(&$this, 'get_stylesheet') );
		}
	} 
	
	public function setLayout($layout = 'mobile') {
		if ($layout == 'mobile') {
			setcookie('xc1-layout', '', time() - 3600);
			setcookie('xc1-layout', 'mobile', time()+3600*24*365);  /* expire in 365 days */
		} else {
			setcookie('xc1-layout', '', time() - 3600);
			setcookie('xc1-layout', 'default', time()+3600*24*365);  /* expire in 365 days */
		}
			
		header("Location: " . WP_HOME);
		die();
	}
	
	private function constants() {
		// Dont like this trailing slash...
		define('MOBILE_THEME_PATH', $this->themeMobilePath . '/' );
		define('MOBILE_THEME_URI', $this->themeChildURI . '/' );
		
		define('MOBILE_THEME_STATIC_PATH', $this->themeMobilePath . '/static/' );
		define('MOBILE_THEME_STATIC_URI', $this->themeChildURI . '/static/' );
		
		define('MOBILE_THEME_CSS_PATH', MOBILE_THEME_STATIC_PATH . 'css/' );
		define('MOBILE_THEME_CSS_URI', MOBILE_THEME_STATIC_URI . 'css/' );

		define('MOBILE_THEME_JS_PATH', MOBILE_THEME_STATIC_PATH . 'js/' );
		define('MOBILE_THEME_JS_URI', MOBILE_THEME_STATIC_URI . 'js/' );

		define('MOBILE_THEME_IMAGES_PATH', MOBILE_THEME_STATIC_PATH . 'images/' );
		define('MOBILE_THEME_IMAGES_URI', MOBILE_THEME_STATIC_URI . 'images/' );
	}
	
	public function get_stylesheet( $stylesheet ) {
		if ($this->desiredView == 'mobile') {
			return $this->themeMobileName;
		} else {
			return $stylesheet;
		}
	}
	
	public static function isMobile() {
		$devices = array(
			'acer','alcatel','audiovox','avantgo','blackberry',
			'blazer','cdm','digital paths','elaine','epoc',
			'ericsson','handspring','iemobile','kyocera','lg',
			'midp','mmp','mobile','motorola','nec',
			'nokia','o2','openwave','opera mini','operamini',
			'opwv','palm','panasonic','pda','phone',
			'playstation portable','pocket','psp','qci','sagem',
			'sanyo','samsung','sec','sendo','sharp',
			'smartphone','sonyericsson','symbian','telit','tsm',
			'up-browser','up.browser','up.link','vodafone','wap',
			'windows ce','xiino','xda','tosh','upg1',
			'upsi','webc','winw','w3c ','acs-',
			'alav','amoi','benq','bird','brew',
			'cell','cldc','cmd-','dang','doco', 
			'hipt','inno','ipaq','jigs','kddi',
			'keji','leno','lg-c','lg-d','lg-g',
			'lge-','maui','maxo','midp','mits',
			'mmef','newt','pant','phil', 
			'prox','qwap','sph-','t-mo','tim-', 
			'vk-v' 
		);
	 
		if( isset( $_SERVER['HTTP_USER_AGENT'])) {
			$agent = strtolower( $_SERVER['HTTP_USER_AGENT']);
			
			foreach( $devices as $browser) {
				if( strpos( $agent, $browser)) {
					return true;
				}
			}
			
			return false;
		}
	}
}

$mobile = new XC1_Mobile();