URLNavigator class.

/**
 * URLNavigator
 *
 * The URLNavigator class extends the Flash built-in method, navigateToURL.
 * This class copies the Firefox browser's link-click action.
 * If you click on a link with the "Ctrl" key held down, the link will be opened in a new window or a new tab, depend on the browser's settings.
 * Or Flash Player tries to download the url, if the "Alt" key is held down.
 *
 * @author: Han Sanghun (http://hangunsworld.com, hanguns@gmail.com)
 * @created: 2008 04 04
 * @last modified: 2008 04 04
 *
 * Modify Histories
*/


package com.hangunsworld.net{
	
	import	flash.net.navigateToURL;
	import	flash.net.URLRequest;
	
	import	com.hangunsworld.net.Downloader;
	
	
	public class URLNavigator{
		
		// Downloader object.
		var dloader:Downloader;
		
		/**
		 * Constructor function.
		 */
		public function URLNavigator(){
			dloader = new Downloader();
		}// end constructor
		
		/**
		 * Handles the URL depending on the properties provided.
		 *
		 * @param ur An URLRequest object.
		 * @param target A String value specifies the target window. [OPTIONAL]
		 * @param ctrlkey A Boolean value indicates whether the "Ctrl" key is held down. [OPTIONAL]
		 * @param altkey A Boolean value indicates where the "Alt" key is held down. [OPTIONAL]
		 */
		public function navigateToURL(ur:URLRequest, target:String="_self", ctrlkey:Boolean=false, altkey:Boolean=false):void{
			
			if(ctrlkey){
				
				// If "Ctrl" key is held down,
				// opens the URL in a new window or a new tab, depend on the browser's settings.
				flash.net.navigateToURL(ur, "_blank");
				
			}else if(altkey){
				
				// If "Alt" key is held down,
				// downlaods the URL via a Downloader object.
				dloader.downloadURL(ur);
				
			}else{
				
				// Otherwise, opens the URL in the window specified by the "target" parameter.
				flash.net.navigateToURL(ur, target);
				
			}
			
		}// end navigateToURL
		
	}// end class
	
}// end package

Usage sample code.

import	com.hangunsworld.net.URLNavigator;

stage.addEventListener(MouseEvent.CLICK, clickListener);


var un:URLNavigator = new URLNavigator();

function clickListener(e:MouseEvent):void{
	
	var url:String = "http://hangunsworld.com/blog";
	var ur:URLRequest = new URLRequest(url);
	
	un.navigateToURL(ur, "_self", e.ctrlKey, e.altKey);
	
}

You can download the class file here.