What is wearable computing? The simplest definition is any electronic device that's designed to operate on your body. A Bluetooth headset would be an easy example, but incomplete. Wearable computing should do more than replace wires. It should compute, communicate, and connect. Thanks to the efforts of companies large and small, wearable computing will soon achieve the potential of its name -- computers so close, they're practically a part of you.

But without accurate information about the world around you, no wearable device will be worth the silicon it's made of. Luckily, sensor technology is a well-developed field, with hardware companies competing intently for prime spots in popular devices. Let's take a look at some of the best bets for this wearable revolution -- and one that's veered off in the wrong direction.

What makes you tick
Many people have already experienced wearable computing -- albeit in a highly simplified way. If you've ever clipped a pedometer to your waist or used a Polar heart rate monitor, you're familiar with fitness computing, a phrase I just made up to describe the wide variety of physical tracking devices already on the market.

Nike (NYSE: NKE) is establishing itself in this arena with a range of tracking devices tied to the Nike+ brand. The Nike+ centerpiece is the FuelBand, a gadget-stuffed bracelet with an accelerometer and a USB port. There are also Apple iOS apps, and sport-specific training sensors for your athletic shoes that make full use of those apps.

Health tracking is a close cousin to fitness tracking. A health sensor might keep track of breathing, sleep cycles, or even stress levels, in addition to simply following motion and heart rate. Some may even be able to diagnose problems before they turn serious. Avery Dennison offers one such device, and expects it to clear regulatory hurdles by the end of the year.

Wearable computing in this form might improve health care as well as your health. Insurance providers might offer discounted rates in exchange for sensor use. Early detection would also do much to reduce costs. Always-on, connected tracking systems might even help reduce the health care industry's administrative bloat, which is a major drag on health care costs in the United States.

This is a part of me
Additional health and fitness information might come right from your clothes -- or even your skin, if you feel so emboldened. Under Armour (NYSE: UA) put an accelerometer in the middle of its signature stretchy shirt that can track left and right sides of the body separately. AT&T -- a company most wouldn't connect to healthy living -- has lent its support (and its wireless connectivity expertise) to Zepyr, the health-tech start-up behind a sophisticated clothing sensor array.

And for the truly connected, Nokia (NYSE: NOK) recently filed a patent for a vibrating tattoo. The tattoo would be activated by magnetic signals from nearby devices. I can't imagine a situation where I'd rather have ink in my skin vibrate instead of the device resting on top of it, but a desperate company might use it as a legal weapon against faster competitors.

Machine to machine
These various sensors (and their descendants) will need some form of wireless connectivity to make use of wearable computing's full power. Simpler devices may be little more than an accelerometer with a wireless controller attached. Texas Instruments and Broadcom (Nasdaq: BRCM) both offer bare-bones Wi-Fi chips that could enable most sensors to communicate with wearable nerve centers with little extra cost or weight added.

Third eye's open
Any wearable-tech user worth their salt will have a head-mounted display such as Project Glass. Those devices already boast some solid image capabilities for products still a long way from public release. A number of image-sensor manufacturers already jockey for smartphone placement, but OmniVision Technologies (Nasdaq: OVTI) may need prime billing more than most. The company's hot-and-cold love affair with the iPhone exposes the degree to which one major device maker can control the fate of its suppliers. A supplier agreement with Google would help, especially if future versions of head-worn technology require two cameras instead of one.

The pieces come together
Sensors will help make wearable computing relevant, but they'll need the right hardware and software support for users to get used to them. Hardware will crunch the numbers, send the information, and keep the pieces connected. Software will make that information understandable and user-friendly, if programmers have done their work.

I've covered those aspects of wearable computing in companion articles that you can read here:

All the data generated by wearable sensors will need to be analyzed. That's a big opportunity for a few well-positioned companies, including one at the heart of this new technology revolution. Find out more about the one stock you need to take advantage of the data explosion in The Motley Fool's free report. Get your copy while it's available.