The most popular handheld devices among adults today are either mobile phones with PDA-like productivity features or PDAs with phone-like communications features. Then there are the plain-vanilla PDAs that pack productivity without the phone.

Just to confuse matters more, all three types run on different operating systems — or rather, they used to. All of that is about to change, thanks to the Windows Mobile 5 platform

Windows Mobile 5 is the Microsoft's latest operating system for handheld devices, which replaces Windows Mobile 2003. One of the broadest features WM5 introduces is a unified underlying platform between the three kinds of device it supports: Microsoft Smartphones, Pocket PCs, and Pocket PC Phones.

The market has proven especially strong for Smartphones, which are "quickly growing in popularity," according to Teney Takahashi, an industry analyst for the Radicati Group. "Features like wireless e-mail, application access and Web browsing have proven to be very valuable for corporations."

Microsoft Smartphones, such as the Cingular 2125 (list $299), are similar to conventional cell phones but offer extra productivity and multimedia features, such as Windows Media Player 10, Hotmail, and MSN Messenger access.

Pocket PC devices like the HP iPAQ rx1950/ rx1955 (list $299) do not offer cell phone functionality, but offer a broader array of applications on the Windows Mobile 5 platform, including Word Mobile and PowerPoint Mobile.

Finally, Pocket PC phone devices, like the Palm Treo 700w (list $500), offer the full WM5 Pocket PC application suite plus Smartphone features. Both Microsoft Smartphones and Pocket PC Phones are typically purchased through providers like Verizon Wireless.

The Cingular 2125 MS Smartphone with Windows Mobile 5

The fact that all three devices now run a unified platform, rather than separate operating systems as before, is mostly a benefit to application developers. Feature sets between devices still differ, but in principle WM5 should allow for more third-party applications to run on both Smartphones and Pocket PCs.

Mobile Memory
The most significant feature improvement in Windows Mobile 5 is persistent memory. In the past, Pocket PC devices could only retain information in memory as long as the battery held a charge. When the battery ran out (or was removed), all your data went with it.

Now, Pocket PCs (and Smartphones) include permanent storage in the form of Flash ROM. That means your handheld will act more like a conventional PC, retaining files and data. But this upgrade includes a trade off — flash memory is slower than RAM, so in exchange for persistence, Windows Mobile 5 boots and loads data more slowly. On the other hand, flash memory uses less power, so battery life of WM5 devices can be up to 10 percent longer.

The Sound of One Hand Tapping
So-called "soft keys" are familiar to cell phone and Smartphone users. Typically these are two buttons just below the display which have no permanent label — rather, their function changes depending on context, signaled by on-screen labels. Soft keys are popular on cell phones because they let you perform one-handed operation in many common tasks. Windows Mobile 5 brings soft keys to the Pocket PC, allowing applications to support one-handed tapping more easily.

Communications Central
Windows Mobile 5 supports the whole range of alphabet soup of wireless communications protocols including Wi-Fi, Bluetooth, EVDO, 1xRTT, GPRS and even GPS. That doesn't mean every Smartphone or Pocket PC includes all the necessary hardware — there isn't yet a device that supports both Wi-Fi and GPS internally, for example. But support in WM5 means that vendors can design Smartphones and Pocket PCs to work with any current wireless communication standard.

The HP iPAQ RX1955 Pocket PC doesn't have phone capabilities, but it packs Windows Mobile 5

Applications Suite
Not surprisingly, Windows Mobile 5 includes the mobile Office suite, with upgrades to Word Mobile (improved formatting of desktop Word documents) and Excel Mobile (improved chart making). It also includes PowerPoint Mobile, which was previously only available as a stand-alone application. Mobile PowerPoint can display, but not edit, presentations.

Smartphones and Pocket PC Phones can take advantage of Internet Explorer Mobile's support for full-screen mode, saving images, loading status, and overall improved page rendering. It offers a more desktop-like browsing experience compared to previous generations of Windows Mobile devices, albeit the limited screen real estate.

All WM5 devices Windows include Media Player 10 and support playback of Microsoft-friendly formats, including licensed content bought from Microsoft-compatible online stores.

WM5's Pocket MSN bundle provides Smartphones and Pocket PC Phones with access to MSN Messenger and Hotmail via the included Outlook Mobile.

Upgrade Paths
If you already own a handheld device with Windows Mobile 2003 (or earlier) operating system, with few exceptions you will not be able to upgrade it to Windows Mobile 5.

You can buy a $40 upgrade for the Dell Axim X50 series Pocket PC. HP is also planning an upgrade for its HX-series iPAQ models, but the release has been delayed until sometime early this year.

Upgrades for phone-enabled devices are even more rare because doing so requires action on the part of service providers, who are more interested in selling new phones. One possible exception is the Samsung i730 Pocket PC phone ($579 with Verizon Wireless plan), which is scheduled for an upgrade to WM5 from Verizon in early 2006.

The Other Blackberry?
Direct-push e-mail between Microsoft Exchange 2003 servers and Outlook Mobile in WM5 provides the sort of real-time communications experience consumers enjoy with that other popular handheld — which is no coincidence. "WM5 is competing primarily with RIM's BlackBerry device for the wireless e-mail component of smartphones," notes Takahashi.

But as Takahashi explains, RIM and Microsoft are approaching the handheld market from different angles. "In RIM's case, the platform and device create a complete package, which seems to be part of the BlackBerry's appeal." Windows Mobile 5, on the other hand, follows in the footsteps of Windows desktop operating systems, supporting a wider range of hardware and software.

Reprinted from SmallBusinessComputing.com

Aaron Weiss a technology writer, screenwriter and Web development consultant who spends his free time stacking wood for the winter in Upstate New York. His Web site is: bordella.com