In September, J.C. Penney set up a test in 16 stores around Houston, in which customers with Web-enabled phones could check on discounts, choose the ones they wanted and then scan special barcodes from their phones into a device at the checkout.

It worked -- to a point. This spring, the department store operator rolled out the program nationwide without the barcodes and the scanners. Now, customers just show a numeric code on their phone to the salesperson who rings up the sale.

Management decided it would be too expensive to buy special equipment for its 1,100-plus stores when the program would work without it. "That's quite an investment," said spokesman Tim Lyons.

In the parts of the business world where talking directly to consumers is critical, dabbling in mobile marketing has become more relevant. But while retailers are paying attention, they're not willing to overcommit to any single technology. Twitter may be hot and iPhone apps all the rage, yet something new could come along next year that will send shoppers in another direction.

Still, business acceptance of the idea of selling through phones and personal electronic devices seems to have gone from skeptical to very interested in the past year or so thanks to the BlackBerrys and the iPhones and the Droids. Consumer use of personal devices connected to the Internet has accelerated, and nobody wants to be left without an address on the information highway, even though it's staking out territory on the fringes because more consumers don't have smart phones than do.

Research firm Nielsen Co. earlier this month released data showing 23 percent of all mobile phone subscribers have smart phones. A recent survey by BIGresearch for the National Retail Federation found more than 50 percent of adults 18 to 34 years old want to be able to surf the Web on their phone.

By 2015, Nielsen predicts "smart phones will be the primary enabler of consumer shopping engagements and new technology innovations will generate additional opportunities for retailers and manufacturers."

By then, the stores and the restaurants and the makers of products need to be comfortable in that landscape. "We're really seeing that as the future of where retail is going as far as with customer interaction," said Mr. Lyons.

He declined to share data on how many Penneys customers are using the mobile service or how often mobile coupons have been used. "It's a very competitive market right now. Everybody's getting into this."

Target has begun offering mobile services, including a monthly text message with exclusive deals sent to registered web-enabled phones. American Eagle Outfitters, based on the South Side, recently tested a text message promotion program called AE MobiLife, thanking participants with a code for $20 off a purchase of $50 or more.

Shop 'n Save and Giant Eagle offer some discounts through Cellfire.com, the same company that handles the Penneys program. Customers with web-enabled phones can browse the deals while they're shopping and then load the ones they want onto their loyalty cards.

There are still more coupons distributed via traditional methods and no one can be sure exactly how far consumers will be willing to go with the mobile services, which generally require them to give out some personal information.

Marketers can't be sure which of the new tools actually will be effective in getting people's attention either.

A year ago, the staff at The Andy Warhol Museum tried Bluecasting for the first time, a term that refers to sending out information for people using Bluetooth wireless communication devices. People who came into the North Shore museum could listen to a clip and then get a discount at the museum shop.

It wasn't all that effective, said Rick Armstrong, the Warhol's communications manager. It turned out that some people's devices blocked the service. And, "The redemption rate -- it wasn't great."

But that won't be the end of it since the majority of the museum's visitors have a smart device of some sort, he said. The staff, working with firms such as Downtown ad agency Brunner, is developing apps and playing with other ideas that might turn smart phones into ways to enrich the Warhol experience, whether in the museum or around other Pittsburgh sites that have connections to the artist.

Brunner last month officially decided mobile marketing was part of the future, launching a Brunner Mobile group with marketing and technology specialists. To try to make the move more than a bland corporate announcement, the agency offered iPads as prizes and a 10-page mobile site to a winning business.

Meanwhile, Dick's Sporting Goods, based in Findlay, has been working with Oakland agency Branding Brand on programs such as its mobile commerce site to make it easier for shoppers using mobile devices to find the information that they want.

In another version of mobile outreach, Dick's has developed a strong Twitter following by making Jeff Hennion, its executive vice president and chief marketing officer, the face of the company in that venue.

Twitter is a free social media program in which messages posted can only be 140 characters or less. Participants can send and receive the messages on their cell phones, if they choose, although they can also use their personal computers.

Mr. Hennion, posting as "dickssportcmo," had 11,529 followers as of late last week. The experiment started about a year ago. He thinks it helped when people realized they could talk to a real person. "It's a little bit of a peek behind the curtain of how things operate," he said.

Some of his posts involve promotions or discounts but he said people respond most to the more personal comments, such as ones about rain at the recent marathon in Pittsburgh. It's a low cost tool that helps the chain stay in contact with customers, Mr. Hennion said.

Twitter is very immediate. Mr. Hennion's account put this message up at 10:12 p.m. June 9, right after Chicago clinched the National Hockey League championship. "Congrats to the Chicago Blackhawks for winning the #StanleyCup. Our Chicago stores just re-opened now with championship gear!"

Fast-food chain KFC used its Twitter account to give out a "secret" password that 100 fans at specific restaurants in various cities, including the Baum Boulevard location, could use to get a free meal last Thursday.

Another mobile tool that retailers and consumer marketers are playing around with is FourSquare, a sort of location-based program that cell phone users can use to let friends know where they are or to comment on a particular place.

The Pennsylvania tourism department last month joined the FourSquare action as a way to promote the state's restaurants, stores, historical sites and museums. Today "visitPA" has collected about 2,000 friends.

It's not unusual for businesses to be listed on FourSquare without the knowledge of those who own them. Any FourSquare user can add a location and make a comment about the place. Anyone who checks in at the same place more than anyone else becomes the "mayor" of that site.

Victoria Dilliott, owner of the Affogato coffee shop in Bellevue, promotes her business through Facebook and Twitter, as well as FourSquare. She offers first-time mayors an Affogato travel mug for $5, instead of the usual $12. Mayors who've been in office longer can get a free baked good with the purchase of a drink.

For businesses, one benefit of FourSquare can be identifying loyal customers and rewarding them. Shops also may get some attention from FourSquare users who are visiting a new area and check their cell phones to find out about nearby stores.

As in every other new medium, the flavor of mobile tools could change as marketers move in.

The SouthSide Works' FourSquare listing showed more than 500 check-ins have been recorded by 260 visitors. VisitPA posted: "With so many local & national retailers to visit, you might want to stop at the Golden Triangle Bike Shop first and bike from store to store."

Meanwhile, The Original Hot Dog Shop on Forbes Avenue showed more than 100 check-ins by 90 unique visitors. Their advice seemed more informal. Gary S. said, "Not as good as when I was a student," while Ben H. weighed in with, "Get a cheesesteak you will not be disappointed."

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