Smart phones are no longer just for businesspeople. Thanks to Apple's iPhone, smart phones have gone mainstream. This Christmas, smart phones will top many wish lists.

For a smart phone to be truly popular, it must have a touch screen. Tappable on-screen controls replace or augment traditional buttons. The iPhone isn't the only touch-screen smart phone on the market. In particular, phones running Google's Android operating system are mounting a challenge.

Palm also has revamped its operating system. And the BlackBerry is a perennial favorite.

APPLE IPHONE

The iPhone is the most obvious choice for smart phone buyers. The iPhone has consistently received kudos from users. And there are 100,000 apps in Apple's App Store.

The iPhone isn't perfect, though. It only works on AT&T's network. Many users have complained of dropped calls and data connections. Consumer Reports lists AT&T's service as mediocre in most cities.

MOTOROLA DROID

Motorola's Droid has received a lot of buzz. And initial sales have been impressive.

The Droid is an attractive, capable phone. Unlike the iPhone, it can run multiple apps at once, although there are fewer apps for Android phones than for the iPhone. Expect more Android apps in the future. There are some good ones currently available, though.

The Droid runs exclusively on Verizon. Consumer Reports ranks it the best service, but that's a generalization; quality varies by area.

PALM PRE

Palm's Pre generated considerable attention at launch. This slick smart phone with a slide-out keyboard uses Palm's new WebOS.

The Pre puts all of your contact information in one place. Data is pulled from your e-mail, contact list and social-networking sites. The Pre offers multitasking. Flip through running apps with a swipe of your finger.

As with the Droid, you'll find relatively few apps for the Pre. And it only runs on Sprint's network. Consumer Reports ranks Sprint last for reliability.

BLACKBERRY STORM2

The BlackBerry Storm2 is RIM's second touch-screen phone, the first being the original Storm. It is a far cry from the BlackBerry loved by businesspeople.

Like the iPhone, the Storm2 does not have a hardware keyboard. But its touch screen depresses and clicks when tapped.

You'll find a fair number of apps for the Storm2, which runs on Verizon's network.

Reach Kim Komando at gnstech@gns.gannett.com.