The Apple iPhone redefined a mobile device, bringing HTML, e-mail, and apps to smartphones. But after 18 months, the iPhone faces its first real competitors. Apple's issues with its 2.x software update, developer complaints over its highly controlled environment, and so-so enterprise support all give the competition an opening.

All the mobile 2.0 competitors support 3G networks, touch interfaces, accelerometers, and location detection services.

The verdict: Although the Google Android platform falls a a bit short, the BlackBerry Storm is right on Apple's heels.

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