So what mobile device should CIOs support? BlackBerry? Windows Mobile? iPhone? A new study from Forrester Research suggests that CIOs will eventually support all of them.Last spring Forrester surveyed some 300 North American companies about their mobile support policies. More than half of enterprises already support more than one mobile device - mostly Blackberry and Windows Mobile devices. Yet the iPhone is coming on strong, with nearly one out of four enterprises supporting the popular device. (European enterprises are taking a more cautious approach to mobile support.)"Enterprises are headed in the direction of embracing multiple mobile operating systems and giving individuals the freedom to choose the platform that's best for them," writes analyst Benjamin Gray in the report. "With this continued shift to Web-based applications, maybe in a couple of years we'll eventually see standards on the browser. Or maybe virtualization will hit handhelds and eventually solve the management conundrum."Some of the report's findings were obvious, most notably that the BlackBerry reigns supreme as the most popular e-mail device in the enterprise, given its reliability, manageability and security. The Blackberry Enterprise Server offers IT managers more than 500 policies for management and security. Three out of four enterprises support the Blackberry.The downside to the BlackBerry, according to the survey respondents, is a lack of flexibility. Enterprises that only support BlackBerry, for instance, risk much of their computing on one vendor. "Since the NTP patent infringement litigation threatened to shut down BlackBerry service worldwide (until the case was finally settled in 2006), firms now more than ever recognize the concern of depending on a single vendor," the report says.Meanwhile, Windows Mobile boasts the best application ecosystem for businesses, such as Office Mobile, according to the report. Forty percent of enterprises support Windows Mobile.Eighteen percent of enterprises also support Windows Embedded CE smartphones, PDAs, and other devices such as kiosks, bar code scanners and imaging devices used by specialized workers. This bodes well for Windows Embedded CE, says Forrester, since the number of task-based workers, which represent 10 percent of mobile workers today, is expected to rise to 15 percent within three years.And then there's the iPhone. CIOs remain cautiously optimistic that the iPhone OS will further develop into a trusted enterprise platform, Forrester says. Of course, the iPhone still lacks some critical management and security features that most enterprises require."These include, to just name a few: device-level encryption that isn't user-configurable, granular remote lock and wipe policies, over-the-air software push (without any dependency on iTunes or the App Store, particularly for home-grown apps), and a central Web-based console to manage the entire life cycle of devices," as well as the ability to stop jailbreaking, the report concludes.What's your mobile strategy? Send me an email at email@example.com. Or follow me on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.