Review: Which smart phone OS works best?

Once only within reach for executives and the well-heeled, smart phones are now at the center of many road warriors' lives. But their popularity has led to a problem: With so many smart phones available now, it's hard to know which one is right for you.

The answer depends on what you most need your smart phone for. Do you need a device that excels at e-mail or one that's optimized for browsing the Web? And will the best smart phone for e-mailing or browsing also keep you entertained on a long flight?

A smart phone's power comes as much from its operating system as it does from the capabilities the vendor builds in. To help you at least narrow down your choices, we tested four smart phones, each based on a different operating system, to find out which platform is better for particular tasks.

To represent their different platforms, we tested Apple's iPhone 3G, based on a mobile version of OSX; the HTC Touch Dual, based on Microsoft's Windows Mobile 6.1; Nokia's E71, based on the S60 variant of the Symbian platform; and Research In Motion's BlackBerry Curve 8310, based on, of course, BlackBerry's proprietary operating system. (For more specific information about the phones themselves, see "About the phones.")

We compared how well these phones performed four common road-warrior tasks: browsing the Web, sending and receiving e-mail, taking a photo and e-mailing it, and playing music and streaming video. We felt these tasks were typical of what most smart phone users need to do, and would also test the power and usability of both the devices and their operating systems.

Here's what we found.