But a couple of years ago, Burkhart noticed that smartphones were becoming powerful computers in their own right. So 18 months ago he started deploying corporate applications on Windows Mobile cell phones, such as a daily profit-and-loss report and alerts that inform managers about staffing or supply shortages. The initial application was deployed in six weeks. Managers can pick between Motorola Q and Treo phones.

The result has been a quicker response time for all kinds of problems. When an Au Bon Pain catering van ran into a customer's car in a parking lot recently, the company's area director didn't need to e-mail someone and then wait around. He used his phone to take pictures of the accident and report it to the people who would have to handle it. "There is a time value to information," Burkhart says, and smartphones let his company get more value for their time.

Au Bon Pain is not alone. Companies that got their feet wet on wireless e-mail with the BlackBerry are primed to move other applications onto smartphones, says Andy Seybold, a veteran wireless consultant. Improvements to smartphones themselves (more memory, better processors) and to wireless networks (they're faster) make such projects more viable, even for small companies. Research company Frost & Sullivan predicts that mobile phone use for field-service applications will increase from 1.5 million subscribers this year to 11 million in 2013.

But obstacles remain. For example, wireless carriers aren't used to selling enterprise systems to companies because enterprises require different types of support than carriers are set up to deliver. Companies are better at getting data into and out of their core applications than providing mobile access to that data. Nevertheless, data integration with enterprise systems poses barriers. Phones have vastly different capabilities and user interfaces. "There's a continuous stream of devices," says Terry Stepien, president of Sybase's iAnywhere, which helps companies make applications work better for remote and mobile workers.

"Some will have keyboards, some won't. Some will have GPS, some won't.They'll have different operating systems. It's a heterogeneous world and it looks like it's going to stay that way."

Companies can try to build their own interfaces to extend applications to mobile phones. They can use a variety of middleware platforms, such as the iAnywhere's Information Anywhere suite, or they can turn to mobile-oriented integrators to do the job.