If there's anything revolutionary, as Apple claims, about the iPhone, it's the user interface that would be nominated. Countless phones make calls, play movies and music, have maps, web browsers, etc., but almost none seem able to fully blend the experience -- which is part of the reason people flipped out at the idea of an iPhone. The device's user interface does all this with panache, but it's not without a number of very irritating issues. Before we get into those issues, however, we should quickly rundown the functions of the iPhone's primarily gesture-based input system.
Drag - controlled scroll up / down through lists
Flick - quickly scrolls up / down through lists
Stop - while scrolling, tap and hold to stop the moving list
Swipe - flick from left to right to change panes (Safari, weather, iPod) and delete items (mail, SMS)
Single tap - select item
Double tap - zooms in and out (all apps), zooms in (maps)
Two-finger single tap - zooms out (maps only)
Pinch / unpinch - zoom in and out of photos, maps, Safari
As you can probably already tell, gestures in the iPhone are by no means consistent. By and large one can count on gestures to work the same way from app to app, but swipes, for example, will only enable the delete button in mail and SMS -- if you want to delete selected calls from your call log, a visual voicemail message, world clock, or what have you, you've got to find another way. Swiping left to right takes you back one pane only in iPod, and two-finger single tap only zooms out in Google maps -- none of the other apps that use zooming, like Safari, and photos.
These kinds of inconsistencies are worked around easily enough, but add that much more to the iPhone learning curve. And yes, there is definitely a learning curve to this device. Although many of its functions are incredibly easy to use and get used to, the iPhone takes radically new (and often extremely simplified and streamlined) approaches to common tasks for mobile devices.
Another rather vexing aspect of the iPhone's UI is its complete inability to enable user-customizable themes -- as well as having inconsistent appearances between applications. Users can set their background (which shows up only during the unlock screen and phone calls), but otherwise they're stuck with the look Apple gave the iPhone, and nothing more. This is very Apple, and plays right into Steve's reputation as a benevolent dictator; he's got better taste than most, but not much of a penchant for individuality.
Even still, Apple's chosen appearance varies from app to app. Some apps have a slate blue theme (mail, SMS, calendar, maps, Safari, settings), some have a black theme (stocks, weather), some have a combination blue / black theme (phone, iPod, YouTube, clock), some have a straight gray theme (photos, camera), and some have an app-specific theme (calculator, notes). Even the missing-data-background is inconsistent: checkerboard in Safari, line grid in Google maps. There's little rhyme or reason in how or why these three themes were chosen, but unlike OS X's legacy pinstripes and brushed metal looks, there's really no reason why the iPhone should have an inconsistent appearance between applications.
Since its announcement, the iPhone's single biggest x-factor has been its virtual keyboard -- primarily because the quality of its keyboard can make or break a mobile device, and of the numerous touchscreen keyboards released over the years, not one has proven a viable substitute for a proper physical keyboard. We've been using the keyboard as much as possible, attempting to "trust" its auto-correction and intelligent input recognition, as Apple urges its users to do in order to make the transition from physical keys. (The iPhone uses a combination of dictionary prediction and keymap prediction to help out typing.)
The whole idea of a touchscreen is a pretty counterintuitive design philosophy, if you ask us. Nothing will ever rid humans of the need to feel physical sensations when interacting with objects (and user interfaces). Having "trust" in the keyboard is a fine concept, and we believe it when people say they're up to speed and reaching the same input rates as on physical keyboards. But even assuming we get there, we know we'll always long for proper tactile feedback. That said, we're working on it, and have found ourselves slowly growing used to tapping away at the device with our stubby thumbs.
As for the actual process of typing, one hindrance we've had thus far is that despite being a multi-touch system, the keyboard won't recognize a second key press before you've lifted off the first -- it requires single, distinct key presses. But the worst thing about the keyboard is that some of the methods it plies in accelerating your typing actually sacrifice speed in some cases. For example, there is no period key on the main keyboard -- you have to access even the most commonly used symbols in a flipped over symbols keyboard. This is almost enough to drive you crazy. (We really, REALLY wish Apple would split the large return button into two buttons: one for return, one for period.)
Caps lock is also disabled in the system by default, but even if you enable it in settings (and then double-tap to turn it on), you still can't hold down shift for the same effect -- it's either caps on, or you have to hit shift between each letter. Also, whether you're in upper or lower case, the letters on the keyboard keys always look the same: capitalized. (This makes it difficult to see at a glance what case of text you're about to input, especially since when using two thumbs your left thumb always hovers over the shift key.) Oh, and don't hit space when typing out a series of numbers, otherwise you'll get dropped back into the letter keyboard again.
We also found the in-line dictionary tool to be more cumbersome than helpful. Supposedly, to add a word that's not in the dictionary, type in your word, then when you get an autocorrect value, just press on that word and the word you typed will be added to the dict file (uhh, ok). But you can also accidentally add words to your dictionary by typing out a word, dismissing the autocorrect dropdown by adding another letter, then backspacing over it. Yeah, for some reason that adds a word to the dictionary file, too. And believe it or not, this confusing little problem caused us to add a number of bum words to the dict file (which you can only keep or clear in its entirety -- and no you can't back it up, either).
On the up side, the horizontal keyboard (which is only enabled when typing into Safari while browsing horizontally) is a much more palatable experience. The keys are far larger, resulting in drastically fewer typing mistakes. (We sincerely hope Apple will enable horizontal input for all its iPhone apps that require keyboard input.) The horizontal web keyboard also has very convenient previous / next buttons for tabbing through fields. The keyboard you're given when entering URLs is one of the most brilliant bits we've seen in the device, and is an incredible time-saver. Since there are almost never spaces in URLs, instead users have shortcuts to ".", "/", and ".com". Finally, the magnification loupe is the best touchscreen cursor positioning method we've seen to date in a mobile device. Too bad you can't highlight and cut / copy / paste text with the iPhone.
So what's the long and short of the keyboard story? We're still getting used to it, but for a touchscreen keyboard it could have been a lot worse -- and a whole lot better. Some among the Engadget staff have been able to pick it up quickly, others, not so much -- your mileage may vary. We have to wonder though, what would it take to get Steve to give us a proper physical keyboard for this mother, anyway? (We already smell the cottage industry brewing.)