Bluetooth . Say the word and your mind is off and reeling. Few brands can rival it for conjuring vivid images of its users--alpha types douchily barking orders between low-fat latte gulps.
For many of us, however, in practice it remains one of those must-have specs with which our deepest interaction is to reckon that "2.0 is better than 1.0, and it does stereo right?" But the truth is you should care about Bluetooth 4.0 because you'll probably end up using it a lot, even if don't know it.
Bluetooth 4.0, you see, is helping distinguish the  iPhone 4S  from its existing and near-future peer devices (most of which sport some variety of Bluetooth 2.0), because it's the first smartphone to have it. But it's also in the recent line of refreshed Macs and soon enough it'll start turning up in phones, tablets, and computers made by pretty much every other manufacturer.
Bluetooth  was created years ago as an international effort, licensed from an official body, to produce a smart, short-range device-to-device radio communications network that could be connected and broken at will. The idea was to simplify pairing mobile devices together, to make it easy to "find" a Bluetooth device and to bring low-power-consumption radio communications to a whole new range of gadgets, iincluding those hands-free headsets you use to chat on your phone while driving (though you know you should really pull over to talk, right?). It was smart, it was relatively cheap, and it did exactly what it said on the box. Of course there were glitches, and some early devices had difficulty talking to each other or even maintaining a good connection, but these were slowly ironed out. Later BT protocols allowed for even lower power consumption (vital when thinking about the limited battery life of, say, a smartphone), simpler pairing, and stereo audio alongside more sophisticated remote wireless control of devices.
And now there's BT 4.0. As part of the new standard, the BT Forum has designed in all of the previous specifications (which it's now archived, and labeled "Classic") and pushed BT tech to the max. Perhaps the most important aspect is the new low-power-consumption mode, and smart-power management that means a BT4 device really only sups on power when it needs to--to the extent that many tiny portable devices could now be powered for significant lumps of time by a common watch battery, sitting idle and almost completely unpowered when not needed (some stats say  a coin-sized battery could push power to a BT4 device on standby for a year).
Right out of the gate this has important implications: A host of medical and lifestyle devices could now sport proper wireless capability and the abilty to "wake" on command. Everything from vital lifesign monitors to health and fiteness devices that put FitBit and Nike+ to shame should now be possible, without the hassle of having to regularly charge components of the system nor worry about pairing them to your smartphone. And because there's this new, low power agreed standard, expect to see many of these devices now communicating with a smartphone directly--instead of with a proprietary interface (like a heart monitor and wristwatch) meaning you can get much more powerful data and analysis right there on the scene.
But Bluetooth 4 is even smarter than that. Its simplest no-code pairing system could allow you to sit your smartphone next to your PC, have them both intelligently and automatically connect up (without all that bothersome messing about in securityspace ) and share data without you having to hook up to your probably already cluttered home Wi-fi network--using more power than BT4 would. That same protocol could let you easily and rapidly share your data between smartphones, when bumped together--in a mode of data communication that was only recently standardized for NFC technology. Or your iPhone could be your secure, wirelessly identified key to automatically log in to your computer.
And this is where it gets interesting. Because part of the pre-iPhone 4S hype  focused on the fact that Apple would include NFC tech and thus jump-start the entire wave-and-pay system. But it didn't show, probably because Apple thinks the system's not yet mature enough. But BT4 is mature, to the point where Apple--fastidious to the Nth degree when choosing hardware--chose that particular brand of chip. Could Apple be planning on pulling off a bizarre coup and start a wireless pay revolution that uses BT4 instead of NFC? All it would need would be a hardware manufacturer on tap to do the interface to a cash register and EFTPOS system, and a specialized app. Unlike trying to pull off this trick years ago, there's now momentum behind the "wave and pay" type of system, and the consumer is warming to the idea.
Plus there're a few technological reasons it makes sense: In some ways BT4's longer-range sensitivity and the fact it can in many cases handle a faster data rate than simple NFC setups lends the tech much better toward some of the advanced wave-and-pay ideas that Apple's been patenting . For example , say a store offers you a discount on the understanding that when you wirelessly pay, it can upload a branded screensaver to your device. See? That's no joke.
[Image: Flickr user azadam ]