There's a ton of debate about Apple's  iPad  this week, of course. But among the celebrations, suspicions and drama one thing's been overlooked. The iPad's killer feature could be not what you view on it, but what you plug into it.
For the first couple of years Apple's iPhone remained a very one-way device: You used Apple's cable and its 30-pin connector, plugged it into iTunes and sent pretty much everything into the phone, only sucking comparatively small bits and bobs of data (photos mainly) back out of the beast. All that changed when Apple released the iPhone 3.0  software for the device, which gave the OS much more powerful control over the kinds of data that could be received and transmitted from third party hardware through its data port.
The change was subtle but, if you think about it, actually very dramatic: The iPhone turned from a tiny, smart handheld phone/web/GPS/entertainment device into a mini computer that you could plug a wealth of peripherals into, kinda like your normal laptop. During the iPhone 3.0 presentation, Apple even made a big play of how this could work, demonstrating  a super-smart diabetes monitoring peripheral that has the potential to transform how sufferers manage their diabetes.
Strangely, interest has died down somewhat--the only bits and bobs of peripheral tech taking advantage of the port have been a few FM transmitters, TomTom's GPS stand/accessory and a few others. The most impressive tech using the port so far has been Apple's own  digital point of sale plug-in, destined for Apple Stores, and a similar device from Verifone. These devices are powerful, and the potential they have to transform how roaming salespersons work inside stores is only just becoming clear.
Why's there not been much excitement in the rest of the tech world about this? My mind, for one, was peopled with a thousand neat little peripherals when I saw the iPhone 3.0 launch, so the lack of plug-ins is confusing. Well...it's probably due to the iPhone's size. It's perfect for a pocket, but sticking in an add-on to its port results in a slightly clunky composite device, and the screen is perhaps a little small for some of the most inventive ways you could use the system.
But wait...here's the iPad. With a 9.7-inch screen and practically the same OS. Apple's already demoed the plug-in keyboard accessory (which transforms it into almost a mini-iMac), alongside a few others like the digital camera connector. It is, in other words, totally capable of dealing with peripherals just like the iPhone, and it's much, much more powerful.
Imagine a roaming point-of-sale device plugged into an iPad--as well as the mundane credit card transactions, with the right dedicated app aboard it could let a sales person look up a stock inventory with ease, tap in an order and even take a customer's name and address. Imagine the medical tech that could exploit the screen--What would you think about all your medical notes being stored on an RFID tag instead of a paper clipboard hung from the end of the bed?Think about doctors viewing x-rays on the device, with pinch and zoom powers to check the details, and wireless transmission to the iPad direct from the x-ray suite.
In fact the number of devices that could benefit from being plugged into a large, light, long-battery-life, always wirelessly-connected, 10-inch portable touchscreen computer with a powerful CPU/GPU are mind-boggling. Might peripherals ultimately be one of the iPad's most successful  features?
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