iPhone 4's new screen and Engineering

Apple, through powers of both good and evil, always finds a way to captivate like no other with their new product launches. But in unveiling the iPhone 4 today, they had an unfamiliar challenge to deal with: a world that has already seen in great detail the new product they were about to announce, thanks to Gizmodo's mega-leak in April. So this time around, Apple had something more to prove: what exactly about the new iPhone 4 is new today?

Screen
We knew the next iPhone would have a higher-resolution screen, but the specifics are in, and they're pretty impressive. 960-by-640 pixels crammed into the same 3.5-inch screen of the 3GS. They're calling it the "Retina Display," and claiming it's the highest resolution screen ever in a phone (it bests the HTC Evo 4G's ginormous 800-by-480, 4.3-inch screen in both resolution and pixel density). Apple is clearly looking to recreate the "wow" factor of the iPad's high-res, color-rich screen by bringing 78 percent of the iPad's total pixel count to a screen less than half its size. Jobs claimed on stage that the human eye, from 10 to 12 inches away, can discern detail in a screen at up to 300 pixels per inch. And the iPhone 4's screen has 326 ppi, which means sharper text and UI elements all around (which will be natively up-res'd to some extent in existing apps).

Engineering
Apple loves their engineering wizardry, and with the iPhone 4, those strange gaps in the side of the frame that to many seemed unfinished have been revealed as something a bit more interesting: the stainless steel rim of the phone does double duty as a multi-purpose antenna for the phone's wide range of radio communications. It's crazy to think of how much transmission takes place, with GPS, Wi-Fi, Bluetooth, 3G data and cellular voice all having their own communications bands. Apple didn't hype any monumental gain in reception, but they did cite the antenna as the key to freeing up more room for a bigger battery that adds 40 percent more talk time.