What's Happening: In the next five years, smartphone use is expected to double. An estimated two-thirds of U.S. residents will carry one, says Michael Grossi, a director at consultancy Altman Vilandrie and Company. That's more than market penetration\u2014it's domination. For CIOs such as Lev Gonick at Case Western Reserve University, the writing is on the wall: laptops are becoming second fiddle. That means CIOs must have an enterprise application strategy for these small, powerful devices.\n\nWhy you care: The barriers to smartphones becoming an individual's main computing device are falling. The Google Nexus One, for example, has Wi-Fi and a 1GHz processor, and it can handle external flash storage up to 32GB. Devices such as the Apple iPad and "smartbooks" (netbooks with 3G access) are essentially oversized smartphones; some business users even run Skype on smartbooks, allowing the devices to double as phones. Gonick concludes, from reports his engineering team provides on smartphone security and adoption rates, that it's just a matter of time before all university employees will be able to do business primarily on mobile devices. Students already do, he observes. And Case Western now offers a smartphone-accessible intranet portal to students that not long ago was designed for laptops.\nTo read more on this topic, see: Is the iPad a Game Changer? and Employee-Liable Smartphones on Corporate Networks: Five Tips to Boost Admin Control.\n\n\nThe Real Deal: For some job functions, such as sales and field support, the smartphone is supplanting the laptop. Other industrious users are accessing web-based enterprise resource planning and customer relationship management applications. "If you don't need to do a lot of heavy spreadsheet work, writing or editing of documents, there's a good chance there's an app for what you need, or if there isn't, somewhere to get one made," says John Jackson, vice president of research at the analyst firm CCS Insight. \n\nHowever, Charles King, analyst with Pund-IT, says that the shortcomings of today's smartphones\u2014poor input capabilities, small displays and a lack of processing power\u2014limit their use as laptop replacements. Gonick adds security concerns to the list. In fact, security remains the widest gap between smartphones and laptops, but it's narrowing. BlackBerry Enterprise Server provides a secure and reliable connection to Microsoft Exchange so companies don't need to be as concerned about regulatory compliance or threats to private company material. And Exchange ActiveSync now works on the iPhone to protect corporate e-mail access.\n\nWhat you should do: Analysts say smartphones will remain complementary to laptops for now. But that will change within five years as functionality improves, processors get faster, and more apps (including support for open-source software) become available. At Case Western, Gonick is preparing for the shift by making sure internal services work on mobile devices. If you don't have a plan for testing enterprise services on smartphones, King says, it's time to develop one. What's more, any new enterprise application you deploy will likely come with a smartphone version. You should view these not as ancillary but as an inevitable part of the future.\n\nJohn Brandon is a freelance writer based in Minnesota.