The Apple iPhone has a big LCD display but it's aspect ratio isn't the same as most widescreens. Apple uses 1.5:1, which is 15% smaller than the 1.78:1 used on most HDTVs.
The specs of the iPhone list a pixel count of 480x320. In and of itself, that doesn't prove anything: some displays utilize rectangular pixels, which allows them to deliver a true 16:9 picture. (Older Hitachi plasma panels, for example, have a 1,024x1,024 pixel count, but their rectangular shape delivers a wide-screen image, rather than a perfect square one might infer from the resolution). But examining the photos of the iPhone on Apple's site reveals a nearly perfect 1.5:1 aspect ratio on the device's 3.5-inch screen when it's viewed in landscape mode. (The images below were snagged from Apple's site, and they compare the iPhone to Apple TV, which offers a true wide-screen image of 1.78:1.)
The nonstandard screen shape means that wide-screen content will either need to be zoomed (cutting off the left and right sides) or letterboxed (black bars on the top and bottom) when viewed on the iPhone