In the U.S., that is - its time came a few years ago in Japan.

Hundreds of thousands of Japanese consumers routinely point their cameras at QR or quick response codes printed on billboards, movie posters, magazine pages, bus shelters, buildings - just about anywhere - to go instantly to a mobile Web page with more information about the advertised product or event or to see a bus or train schedule.

It saves thumb-typing long URLs - and it's kind of cool in the tech-nerdy way the Japanese seem to like.

Now ScanBuy Inc., a U.S. firm, has launched the first major trial of this technology in North America.

Two ScanBuy customers in San Francisco, CitySearch magazine and Antenna Audio, are posting codes in restaurant windows and at tourist attractions. Users who download and install the ScanLife software on their phones can point the camera at a code, click one button and instantly be taken to a Web page with reviews of the restaurant or information, including streaming audio clips, about the attraction.

The two-dimensional (2D) codes and the reader software ScanBuy deployed in San Francisco in March are a little different from the technology that has been used in Japan since 2004. But more importantly, ScanBuy is proposing quite a different business model.

"The Japanese [experience] proves that consumers love this and that the technology works," says the company's CEO Jonathan Bulkeley. "It's just a question now of what the business model is going to be."

That's in fact only one of many questions around the technology. The most crucial, perhaps is can it be transplanted from the rarified atmosphere of the Japanese market?

In a multi-part series beginning with this article, we'll look at how mobile 2D barcoding works, why it evolved first and differently in Japan, and where it's likely to go next.

But first a little context.

The notion of using a cell phone to read bar codes is arguably part of a larger trend to using mobile devices for more, and more disparate, applications, and in particular, using them as a kind of universal interface between digital and physical or analog worlds.

Michael Liard, research director for RFID at Allied Business Intelligence Inc. (ABI Research), says 2D barcoding should be considered in the same context as parallel and possibly competing technologies such as near-field communications (NFC).

NFC, a wireless radio technology now being built into some mobile devices, uses the ISM band (13.56 MHz) to instantly connect devices at speeds between 106 and 424 Kbps over very short distances. Its most important application may be enabling RFID-based (radio frequency identification) applications such as contactless payment.

There are already areas of overlap between NFC and 2D barcoding, Liard points out. Companies in Japan, for example, have experimented with putting NFC tags on movie posters.

A consumer could wave an NFC-capable mobile device near a poster and the data received from the tag would automatically point their mobile browser to a Web page with information about the movie - or enable a transaction to purchase a ticket.

"Ultimately, what's the legacy going to be?" Liard wonders. "Is it going to be NFC, is it going to be 2D barcodes?"

He believes it may be only one or the other, not both. In markets outside Japan and Korea where neither has had much impact, it's pretty much a "blank slate," Liard says. It could go either way.

But barcoding itself is not a single uniform technology or set of capabilities. Standard 1D barcoding - more about the difference between 1D and 2D barcodes in a moment - is also on the table. Or rather, it's still on the table.

As far back as the late 1990s, Digital Convergence, now defunct, marketed a device called the CueCat, a low-cost scanner for reading standard 1D or UPC barcodes. It plugged into a computer and let users scan barcodes on magazine ads to take them directly to a Web site with more information about the advertised product.

It was the same notion of automating Web browsing, just not in the mobile environment.

Fast forward to 2008.

Ecrio Inc., a Silicon Valley company, is developing products and business models for using standard 1D barcodes in consumer advertising and retailing in the mobile space. But Ecrio is not so much interested in using mobile devices to read barcodes as to send them.

The idea is that consumers can go to a Web site and download a 1D UPC code to their device. The code is in effect an electronic coupon. At the point of sale, they aim their mobile device at the retailer's barcode scanner, press a button and it emits the code using IR or some other light source.

What's the point? It saves consumers carrying around clips of coupons - and retailers processing them. And it gives advertisers new ways to help consumers make the jump from the Web to buying decisions in the physical world.

It could also work in conjunction with 2D barcodes, says Larry Loper, Ecrio's vice president of marketing. The consumer scans a 2D barcode, goes to the company's Web site, decides he likes the product and downloads the barcode-based coupon to get a Web discount - or free sample.

"Our problem with the existing use of 2D barcodes is that it doesn't close the loop on redemption," Loper says. "It doesn't allow you to get a receipt or a coupon. But we always see the two technologies as something that can partner together."

Ecrio, a 3G applications developer, would ultimately like to see cell phones with the ability to emit barcodes. Some already have the basic technology onboard with IR or other kinds of emitters, such as the LEDs on BlackBerries. The problem is getting access to the hardware layer to control the emitters with software.

The company has produced prototypes with a few devices, but until the cell phone makers see a strong demand for this - most likely from advertisers and/or retailers - they likely won't go out of their way to cooperate, Loper concedes.

In the meantime, the company has developed a thumb drive-size USB device inexpensive enough that retailers can give it away to consumers. It plugs into a computer to download coupon codes from Web sites and has an IR emitter for delivering coupons at point of sale.

Ecrio has trials underway in France, Australia - and with an as yet unnamed grocery chain in the U.S. southwest.

One dimensional barcodes, which actually are an array of bars, encode a relatively small amount of data, typically a string of numbers - not enough to contain a URL, for example. 2D barcodes were developed for applications requiring printable codes able to hold more data.

QR, developed originally for inventory applications, is one. The technology ScanBuy uses, EZcodes, developed at a Swiss university and licensed exclusively to ScanBuy, is another. It was developed specifically for marketing applications. A third contender is Data Matrix, developed by Acuity ciMatrix, which was acquired by Siemens in 2005.

2D codes all look somewhat similar: a square outline with a two-dimensional matrix of black and white shapes inside, similar to a very simple bit map. Indeed, QR codes can encode coarse-grained images.

Code-reading software on the mobile device integrates with the phone camera. Simply pointing the camera at a code with the software running will start the recognition process. It doesn't require the user to actually "take a picture" of the code. And it is very fast.

It's possible to develop software that can read any known 2D code. Indeed, ScanBuy's ScanLife software is code agnostic. It can also read QR and Data Matrix codes, although Bulkeley believes EZcode will ultimately dominate this space.

The codes can automatically trigger a range of actions on the mobile device: visit or bookmark the URL for a WAP or standard Web site; send a text or e-mail message; download content such as wallpaper, ringtones, games or video clips; save or update a person's contact information; send or save an appointment or date; place a phone call without dialing the number, and so on.

The most prevalent use in Japan has been automated Web browsing, usually advertising-related - navigation to a site using the mobile device's WAP browser - or automating a call to a contact center so the user can request more information or initiate a transaction.

But codes on bus shelters in Japan will take the user to a Web site with updated bus schedule information related specifically to that location. 'The 86 bus will arrive in 2.5 minutes.'

Developers such as Luna Development, a Toronto-based 3G specialist, are fermenting lots of other application ideas. Indeed, the possibilities seem limited only by the human imagination.

The trouble is, none is likely to succeed until a critical mass of users has code-reading software on their mobile devices. It's the old chicken and egg dilemma.

How will it be resolved? Check back for Part II of this series to find out.