Increase security for code-entering on the iPhone

I just had an idea to increase security whilst entering your code into the iPhone lock screen (or any other similar application).

It's quite easy to see what numbers you are typing, even from a distance. That's mainly because the asshole on the next table just needs to take a look at the pattern you're typing on the screen.

Now, what if the keypad (displayed in a conventional format) will have the numbers ordered in a random fashion?

Would definitely make it a lot harder to get your code.

Feel free to use this idea for an application but don't forget to send me a copy :)