In iOS 6, Apple has added the ability to display a web page in full screen using Safari.
1. Open Safari on iPhone.
2. Navigate the web page you want to see in full screen.
3. Rotate your iPhone into landscape mode.
4. Tap on the button in the bottom right corner, two arrows pointing in opposite directions.
Now you are viewing webpage in full screen mode, to return to normal mode, again tap on the same icon.