I've been saying it for three years: Touch computing represents a third wave of computing that will wash away today's graphical user interface (in the same way that graphical computing killed the command line).
I've speculated about who will grab major market share and control this market, and I've tended to favor Apple. The reason is that, as the company proved with the iPhone and the iPad, Apple truly understands the importance of user interface (UI) design in general, and the importance of multitouch, physics and gesture-based computing in particular.
Apple has proved visionary with its touch computing products. And it has demonstrated creative brilliance in providing limited elements of touch computing under the constraints of today's technology (and the cost of that technology).
A lesser company would have shipped products with inadequate compute power or charged too much for those products or both -- as Apple did with the original Macintosh (when Apple was a lesser company). That's what Hewlett-Packard appears to be doing with its Slate tablet.
I think it's very likely that Apple will, for the foreseeable future, have the best touch tablets. I just don't think they'll own the market. Here's why.
The paradigm that launched a thousand form factors
Annoying Silicon Valley-speak aside, understand that the touch UI lends itself to a wild variation in hardware types.
The graphical-computing UI, which was invented by Xerox PARC in 1973 and which we're still using today, lends itself to two form factors.
Because the GUI needs both a keyboard and a mouse, the desktop form factor largely dictates certain attributes, namely a keyboard here, a screen there, a mouse on one side or the other and cables everywhere. The mobile form factor that works for GUI computing is the ol' clamshell approach, with screen in the lid and keyboard on the bottom.
Yes, there are many other form factors for PCs, including all-in-one desktops and convertible pen-input tablet PCs for mobile computing. But in the larger market, those fringe devices are rare to the point of irrelevance.
That isn't the case with touch computers. Because you don't need anything but fingers to use a touch computer, touch computers will be everywhere you find fingers. In a few years, giant screens and massive processing power will be cheap.
The "ubiquitous PC" concept futurists have been talking about for years will find its interface. And the mobile computing revolution will continue unabated, making us less likely to chain ourselves to desks.
However, when we do sit down in our offices, many of us will use something that works (but hopefully doesn't look) like this. The standard touch desktop PC that you'll buy, say, a couple of years from now, will be usable in three positions: flat like a table, upright like a big-screen TV (for presentations) and at an angle, like a drafting table, for everyday work.
But that's just the beginning. Here are just a few of the major form factors that the touch-computing revolution make all but inevitable:
The pen-and-touch PC
I've always hated the experience of using a stylus. The early smart phones all had them. Windows-based tablet PCs have them.
I've believed for several years that touch computing would destroy pen computing. It turns out that the problem with tablet PCs isn't that they support pen. It's that they don't support touch.
But a video from Microsoft Research convinced me that a system that combined the two modes of input would clearly be superior to one that, like the iPhone and iPad, doesn't recognize a pen unless it's made out of meat.
Microsoft Research has been hard at work for some time solving touch-display problems that wouldn't occur to most of us -- such as, "What's a touch PC to do when a body part touches the screen incidentally, rather than deliberately?"
For example, what happens when the heel or the outside edge of your hand touches the screen? In one patent, Microsoft recognizes this body part as a command -- it brings up half a keyboard under the palm. Place the other heel somewhere else on the screen, and you get the other half of the keyboard. Nice!
With Microsoft's pen-and-touch technology, when the system detects both a heel and a stylus tip, the system goes out of its way to ignore the heel. It's just the hand resting on the screen for more natural writing with the pen.
Interestingly, the presence of a pen increases the possible range of gestures dramatically.
Business users will love the addition of pen. For starters, it enables them to sign things. (Maybe we'll finally be able to unplug the fax machines for good.) But so will graphic artists, people who like to doodle -- whatever. Even if you hate using a stylus, a device that accepts input via both a stylus and hand gestures shouldn't degrade the touch computing experience for you -- you don't have to use the stylus if you don't want to.
The clamshell touch notebook
Microsoft sorta-kinda hinted at a usage model that involved a two-screen laptop with its Courier touch device. The idea appears to be to limit the device to a small subset of uses, such as those who need a gadget just for taking notes or keeping an appointment book. The Courier project also envisions combining touch and pen input.
Designers working with the One Laptop Per Child project had an even better idea: a laptop that could be used in four different ways. In one configuration, for example, it could be used like a regular clamshell laptop, with the bottom screen displaying an on-screen keyboard. In another configuration, it snaps out flat to form a touch computer like the iPad, but twice the size.
This might one day become the dominant form factor for mobile touch computers, bigger even than the iPad-like single screen, if for no other reason than the screen can be a lot bigger.
The embedded touch computer
Because touch computers enable us to control computers using nothing but a sheet of glass, they can be embedded into almost anything: car dashboards, refrigerators, TV remote control units, coffee tables, kitchen counters, bathroom mirrors, airplane tray tables and more. Your desktop PC might be built into your actual desktop.
Beyond merely controlling devices they're built into, embedded touch PCs can link us to cloud-based applications and data. Log into your bathroom mirror and check e-mail while shaving in the morning. When junior e-mails you the picture he finger-painted using his preschool iPad, you can use a virtual magnet to attach it to the refrigerator for all to see. The possibilities are endless.
It's worth pointing out, by the way, that the first-ever significant multitouch device to hit the market wasn't Apple's iPhone, but Microsoft's Surface computer, an embedded touch computer built into a coffee table.
Why Apple won't play
I personally find all of these form factors really exciting and compelling. But Apple will see them as a sideshow that diverts the world's attention from its perfected vision of the single-sheet-of-glass PC.
The iPad is a great example of Apple's vision of the Zen-like interface. The front is nothing more than the single sheet of glass and a single button. Do you think Apple designers are sitting around thinking about what they can add? If so, you don't know Apple. Instead, they're working night and day to see how they can get rid of that button.
Apple will transition its entire line of computers to touch-controlled systems like the iPad. But I believe they'll go minimal. All their systems will aim to perfect a single vision of the computer interface as all touch and nothing more.
I expect these systems to be breathtakingly beautiful and thrilling to use. But I also expect the company to take a pass on the many options that touch enables.
Microsoft, Google, the Linux people and all their partners, on the other hand, will jump all over it and usher in an incredibly diverse range of computing options involving touch, as well as systems featuring combinations of touch and every other input mode they can think of.
In other words, the touch-computing market of the future will look a lot like today's market. Apple will do its vision thing, and it will offer a very narrow range of really elegant devices that persuade a minority.
But I don't see them even trying to participate in the incredible range of form factors that touch enables.
Touch ushers in a whole new world of hardware and usage possibilities. But, as always, Apple will continue to live in its own world.
Mike Elgan writes about technology and global tech culture. Contact Mike at mike.elgan@elgan.com, follow him on Twitter, or read his blog, The Raw Feed.