The iPhone features the most attractive display we've ever seen on a portable device of this size, by far and bar none. While its 160ppi resolution isn't quite photorealistic, the extremely bright 3.5-inch display does run at 480 x 320, making it one of the highest pixel-density devices around today (save the Toshiba G900's mind-popping 3-inch 800 x 480 display). But pixel density doesn't necessarily matter, it's how your device uses the screen real estate it's got. Instead of printing microscopic text, as Windows Mobile often does with high resolution displays (see: HTC's Universal and Advantage), iPhone text looks smooth and natural in every application -- everything on-screen is eminently readable.
The screen also provides an excellent outdoor viewing experience. With optical properties reminiscent of transflective displays, the iPhone remains completely readable (if a only bit washed out) even in direct sunlight. Unfortunately, the display's viewing angle left a little something to be desired, and the rumors about the glass face being an absolute fingerprint magnet are totally true: this thing picks up more smudges than almost any touchscreen device we've ever used. Honestly though, we'd attribute this to the fact that unlike most other smartphones, you are exempt from using a stylus on the iPhone's capacitive display, meaning you must touch it with your bare finger to do almost anything.
Thankfully, like the rest of the phone, the glass face feels extremely sturdy, and one should have absolutely no hesitation in wiping it off on their jeans or sleeve -- we've yet to produce a single scratch on the thing, and we understand others testing under more rigorous circumstances (like deliberately trying to key its face up) have also been unable to mar its armor.