After weeks of poking, prodding, and tapping on screens, we found the answers. We put the BlackBerry 4.1, Palm 5.4, Symbian 9.2, and Windows Mobile 5 operating systems through the wringer, checking their strengths and weakness in areas such as e-mail, multimedia, Microsoft Office compatibility, and ease of use. We looked at the number (and quality) of third-party applications, which can make the devices more like pocket computers than pocket organizers. And we delved into the core apps themselves to see which OS does the best job managing your contacts, calendars, and other critical info. Read on to see how they compare.

Palm
Ease of use and solid PIM apps have always been a hallmark of the Palm OS. See what else it has to offer.

Windows Mobile
Windows Mobile 5 offers more than just a stripped-down version of Microsoft's Office suite. Multimedia, anyone?

BlackBerry
Find out why BlackBerrys have earned the CrackBerry nickname and what the future holds for these devices.

Symbian
Though not as well known as the other OSs, Symbian brings solid productivity tools and versatility to the table.

Which OS is right for you?
Now that you have an overview of each OS, find out which one is best for you and check out some of our top product picks.

The Palm OS is currently in a state of flux. Its developer, PalmSource, was acquired last year by Japanese software maker Access, after spinning off from Palm a year earlier. Palm OS 6, code-named Cobalt, has been dead in the water since 2003 with not a single manufacturer, Palm itself included, releasing a device with the updated OS. All of Palm's latest models run a variant of Palm OS 5 (version 5.4, in most cases), which is now more than three years old. Fortunately, however, what was good then is good now. Save for a few multimedia shortcomings, the Palm OS is still a solid OS.

Ease of use
Simplicity has always been a hallmark of the Palm OS. Although version 5.4 packs more features than ever, it's arguably just as easy to operate as the first version. To run a program, tap its icon. To enter data, write onscreen using the character-recognition software or tap-type on the virtual keyboard. Everything about the OS seems logical, intuitive, and uncomplicated. We particularly admire the way the Palm OS manages applications. You never have to "exit" a program the way you do on a PC--you just switch to a different one. And unlike some operating systems (yes, we're looking at you, Windows Mobile), the Palm OS never gets bogged down by multiple memory-hogging apps running simultaneously.

	Palm Treo 650 (click for full review)

Core applications
Already solid when they debuted back in 1996, the Palm OS's core apps have only improved over the years. For instance, you can now attach a photo to a contact--a particularly wonderful feature for camera-equipped models such as the Palm Treo 650. The Tasks applet has added new buttons for quick sorting by date and category and lets you assign alarms to your tasks. In short, Palm's core apps continue to combine power and simplicity, and we still rank them tops among PDAs.

Desktop compatibility
Palm OS PDAs offer two desktop-synchronization options: Outlook and Palm Desktop. The latter is a fairly robust information manager that has the advantage of being much more novice-friendly than Outlook. It also supplies the tools you need to copy photos and videos to your device, install new programs, and set up your e-mail.

Office compatibility
Though not an inherent part of the Palm OS, DataViz Documents To Go comes standard on nearly every Palm handheld (the sole exception being the Palm Z22)--so we'd be remiss if we didn't consider it. The program automatically syncs Word, Excel, and PowerPoint documents between your Palm and your PC while keeping them in their native formats (meaning you can also instantly view documents received as e-mail attachments--no conversion required). You can edit Word documents and Excel spreadsheets and compose new ones, though PowerPoint files are read-only. The software also supports PDFs.

	Palm TX (click for full review)

E-mail
Palm's VersaMail program has the enviable ability to fetch e-mail over a variety of connections: Bluetooth, Wi-Fi, or even desktop synchronization, the latter relying on your PC's Internet connection for mail commerce. The applet itself is solid, supporting multiple POP3 and IMAP accounts, embedded images, and virtual private network (VPN) connections.

Multimedia
Although most Palm handhelds offer high-resolution screens and digital audio capabilities, the Palm OS isn't the multimedia juggernaut it could be. For instance, you need third-party software (NormSoft's Pocket Tunes Deluxe) to play DRM-protected songs, the kind you get from online music and subscription services. Palm bundles Pocket Tunes with some models, but the DRM-capable Deluxe version will cost you extra.

As for movies, Palm's Media applet can play them, but only MPEG-1 clips converted by Palm Desktop. For anything else, you'll need third-party software. In fact, to watch a DVD, you'll need two programs: a desktop converter and a handheld viewer. And if you want to play TV shows recorded on a Media Center or TiVo--something Windows Mobile devices can do fairly easily--you're pretty much out of luck.

Third-party apps
In terms of sheer volume, the Palm OS continues to have an edge when it comes to third-party software. Users can draw from more than 20,000 applications to extend the functionality of their handhelds--a number still unmatched by the Windows Mobile platform, though this is steadily changing. This isn't to say that software available for the Palm platform is better, only that there's more of it. And more software means more potential functionality.

Windows Mobile

Originally regarded as little more than Microsoft's answer to Palm, the Windows Mobile (formerly Pocket PC) operating system has come into its own. Last year's release of version 5 brought some much-needed improvements, including smarter mobile versions of Word and Excel, direct-push technology, and persistent storage.

Ease of use
Windows Mobile is the better contact manager, offering a lot more data fields than the Palm OS and an easier method of searching large lists. Tapping address-book-like tabs brings you to names starting with those letters. Even if you have 1,000 contacts, usually you can find the one you're looking for with just two or three taps. It's worth noting that all Windows Mobile devices let you record voice memos--a core function of the OS--while only some Palm OS models do. The Calendar function on Pocket PCs is on a par with Palm's app, but we just say the latter offers a superior to-do list, if only because it organizes everything more logically.

	HP iPaq hw6965 (click for full review)

Core applications
Over the years, Microsoft has made few changes to the Calendar, Contacts, Notes, and Tasks applets. They're capable programs that sync well with Outlook, but we wish Microsoft would gussy them up a bit; they're pretty stark. Windows Mobile 5 brought only one noteworthy improvement: You can now assign a photo (and ring tone, if you have a smart phone) to an individual contact.

Desktop compatibility
The Windows Mobile OS syncs with Microsoft Outlook and only Microsoft Outlook (though a third-party program called the Missing Sync allows for synchronization with Macintosh systems). The recently updated ActiveSync 4.1 utility makes this a seamless, nearly instantaneous affair--though Microsoft inexplicably removed a few desirable features, such as the option to sync via Wi-Fi.

	Dopod 838 Pro (click for full review)

Office compatibility
With the arrival of Windows Mobile 5, Microsoft finally added native file support to its Word and Excel applets. Translation: It's no longer necessary to convert desktop documents to the Mobile format--a process that stripped most of the formatting. As for the applets themselves, they've improved as well, with long-overdue features such as a spelling checker and support for embedded tables and images. And finally, there's a PowerPoint viewer called PowerPoint Mobile.

It still shocks us, however, that Microsoft offers no convenient way to synchronize Word and Excel documents with their desktop counterparts--unless you relocate everything to a special folder.

E-mail

	O2 Xda Atom Exec (click for full review)

E-mail got a big boost with Windows Mobile 5 with the support of direct-push technology. Available through Microsoft's Messaging and Security Feature Pack, it allows you to receive messages in real time. Otherwise, the Outlook applet hasn't changed much, except for the name (Outlook Mobile was formerly known as Messaging). It can transact mail via Bluetooth, Wi-Fi, GSM- and GPRS-type connections, and desktop synchronization.

Multimedia
No other platform can touch Windows Mobile when it comes to multimedia. Right out of the box, it supports DRM-protected music (meaning you can play songs purchased or downloaded from various online services) and TV and movie recordings from Media Center PCs and TiVo boxes. Most recently, Sling Media launched SlingPlayer Mobile for the Windows Mobile operating system, letting you watch your own TV on your handheld.

Third-party apps
If there's a function you want your Windows Mobile PDA to perform, chances are good there's a program that can do it. Sites such as Handango and PocketGear are home to thousands of third-party applications--and some of the best games you'll find on any PDA platform. Among the more celebrated Windows Mobile titles are Age of Empires, Quake Mobile, and Myst for Pocket PC.