This, really. My iPhone 4 has a screen protector sheet on the front, and nothing else. I used to have a protector sheet on the back, and sometimes had some other form of protection such as a plastic shell or silicon jacket. Over time, I've decided that cases just make the phone unnecessarily bulky. After months of normal use, the back still appears unscathed. It has survived 2 falls, both nearly 6 feet from a key rack onto a doormat on top of a tile floor. I'm considering taking off the screen protector on the front. Since it's just a static sheet it's fairly unobtrusive, so I may end up keeping it just in case. As always, your mileage may vary.
http://www.incipio.com/iPhone-4-4S-...4-4S-NGP-Matte-Semi-Rigid-Soft-Shell-Case.asp I had my iPhone 4 in an Incipio NGP case, perfect fit and it protected the screen reasonably well with the raised lip. Smooth enough to easily go in and out of my pocket, but grippy enough to not slip out of my hand. Adds very little thickness to the phone, and it softens the hard edges on it making it easier to hold. I didn't like the iPhone 4 until I bought that case tbh, seemed too fragile to even put it down on a table without some cloth. And in response to your question, the iPhone's screen definitely scratches. My sister's iPhone 4 has never been in a case, and it looks like crap after a year. Deep scratches all over the front and back, and the antenna band is all scratched and dinged...
I don't treat mine like a precious item, but I'm also not on the other side of the spectrum with people who keep their smartphone in the same pocket as their massive bunch of keys, and never put a screen protector on it, and throw it around like they think it's made of rubber. My phone has a screen protector and case on it. I try not to drop it, although it's had a couple of bumps which the case has protected it against, and I certainly don't keep it in the same pocket as my keys. I'm not actually trying to keep the resale value of my phone as high as possible, I just hate pretty, shiny things that don't look shiny and pretty any more. That's why I'm a car detail freak, see? My cars paintwork being scratched and scored, or even going for a fortnight without being washed and valeted would really annoy me, as would a beat up looking iPhone in my pocket and hand every day Note: I'm still rocking a 3GS, not a '4. I actually have two now, one is a spare that I bought cheap off eBay and repaired.
