Samsung one-upped itself and gave the Galaxy S III one of the biggest displays available for smartphones. It's the latest example of a trend by iPhone competitors to push larger screen sizes to differentiate themselves. The first Galaxy S phone had a 4-inch screen, and Samsung moved up to 4.3-inch on the SII. The S III, with its 4.8-inch screen, or the HTC One X's 4.7 inches, dwarf the iPhone, which has had a a 3.5-inch since 2007.
With Android phones getting bigger every year, how big can they get until they are simply too big to use as phones? Many people already find 4.3-inch displays too big to operate with one hand, and the "bigger is better" philosophy could bite back at Samsung and other iPhone competitors. At this rate, next year we could see a display larger than 5-inch (similar to the Galaxy Note), which will be big enough to cover your face while you're on the phone. If this trend continues, you could be sporting a 7-inch tablet as a phone soon.
The Samsung Galaxy S III is only outbid in the screen size department by the Galaxy Note, whose 5.3-inch display is the biggest on a smartphone so far. Even Samsung's own advertising campaign is unsure whether the Note is a phone or tablet, but Samsung clearly markets the S III (and its 4.8-inch display) as a smartphone.
Larger screen sizes have their obvious advantages. The keys of the virtual buttons are larger and easier to press by those with big fingers; they're great for watching videos; and not least, the larger surface of the phone allows for a thinner profile -- thinner than the iPhone or the HTC One X. See how the specs of the Samsung Galaxy S III stack up against the HTC one X and iPhone 4S.
With each iteration of the Galaxy S series, Samsung pushed the screen size. The Original Galaxy S had a 4-inch display, which went up to 4.3-inch on the Galaxy S II, and is now up to 4.8-inch for the S III. Yet the S III still features physical buttons for menu and navigation control, which means that for one-handed use, you must stretch your fingers to reach different parts of the screen. During this time, the iPhone maintained its 3.5-inch screen and Apple worked instead to make its display sharper.
Despite their big and bright screen, Samsung Galaxy phones don't match the pixel density of the iPhone's Retina Display (326ppi), for which the phone has received continuous praise. Actually, the bigger the screen got, the lower the PPI count was; for example, the Galaxy Nexus has a 4.65-inch, 1280-by-720 pixel display with 315ppi, while the S III maintains the same resolution for 4.8 inches, taking the density down to 306ppi.