Now you can inspect DOM elements, profile Javascript/CSS and debug on iPhone/iPad using the latest iOS 6 iPhone and iPad simulator along with the latest Safari 6.

To get started you need the latest version of Xcode 4.5 to run iOS 6 on the iPhone and iPad simulator and Safari 6 installed on your Mac. Currently Safari 6 is available for Lion and Mountain Lion.

Once you have the iOS 6 simulator and Safari 6 installed and running, click on the Develop menu of Safari 6 and you should now see iPhone Simulator or iPad Simulator menu item listing all the webpages that are available to debug in Mobile Safari via Safari 6 Web Inspector. You will also see native apps show up in this menu item if the application is running and you can debug UIWebView using this method as well.

With the latest Web Inspector you can change css properties on the fly just like you can on desktop browser and can profile Javascript and CSS along with seeing the network traffic. Plus you can put break points in your Javascript code and inspect variables and use the Javascript console to try out code changes.