In-Stat predicts the year-over-year growth rate for spending on wireless data business applications will drop to 44 percent in 2008, down from 50 percent in 2007.

The company also says that spending will continue to grow 30 percent each year through 2012.

The last 10 years have seen businesses nearly double their usage of mobile business applications each year, In-Stat says, but U.S. enterprises are reaching a saturation point.

Wireless e-mail, wireless Internet access, wireless instant messaging and personal information management (PIM) tools are by far the most widely used horizontal business applications (suited for use by a variety of employees,) since they prove simplest to deploy, according to In-Stat. In 2007, 88 percent of companies surveyed by In-Stat used wireless e-mail, 84 percent provided wireless Internet to their users, 65 percent employed mobile instant messaging applications and 60 percent managed business information, such as calendars and contacts, via mobile devices.

"As business users approach saturation for horizontal mobile data applications, most of the growth potential remains for vertical market applications," specialized for sales forces, for example, said Bill Hughes, In-Stat principal analyst, in a release.

The number of business users with corporate smartphones jumped 34 percent last year, the company says. An earlier In-Stat report predicted that the overall global smartphone market will increase by an average of 33 percent per year during the next five years.