This is how I do it
Requirements: Safari,Jailbroken Itouch or Iphone internet connection
1. Open up Cydia, and search for "ScreenSplitr" and install
2. Turn on the application by opening the app(it will then get you out
and say ON on the icon)
3. Open Safari on your computer and go to all bookmarks,then click "Bonjour"
4. You'll see a link with the name of your iphone,open that.
5. Once you click that, a message will pop up on your iphone. Click "accept"
6.Your Done, your iphone's screen is now in a safari window.