Totally agree. All of the people saying, 'I've had my iPhone for 2 years with no film and the screen is scratch free' - I call bullsh*t. Take a high resolution picture at the right angle and I pretty much guarantee it'll be scratched. It sure as hell won't be perfect like the day you got it. Just because it doesn't have a huge, immediately noticeable gouge out of it doesn't mean it's not scratched.
I think the 3G/3GS iPhone in generally is pretty delicate for a phone. Even with cases on, the chrome bezel gets scratched to hell, the back cases can crack regularly. They're tougher than some smartphones, but certainly not bullet proof. I've seen countless people with smashed screens still forced to use them because they didn't take insurance and it's too much to get it fixed or replace. They need care!
The original 2G iPhone I had took some real abuse with no cover or screen protector and heavy use. The screen was scratched to hell by the time I upgraded, hence babying the 3GS with a PowerSupport case and screen protector.
Also, if you want to ensure no bubbles when you put a screen film on:
- ensure your hands are washed and dried thoroughly
- clean the phone screen with lint-free cloth
- do it in as dust free environment as possible and clean the surface with the same lint free cloth too.
- When you're applying the film, start from the top and do it bit by bit and use the cloth to smooth out the laid film as you put it down.
- then push any air bubbles you do get to the sides.
- You can also hairdryer the film when its on, pushing the bubbles to the sides. That can help.
It works for me every time. Actually getting it perfectly straight seems like the harder thing to do.