A bundle of potential in a ball

The Sphero from Orbotix.

You might remember in the movie Field of Dreams a mysterious voice in Kevin Costner's head kept intoning: "If you build it, they will come." It took some time for him to realize that somewhat unspecific piece of guidance really meant: "If you build a baseball diamond in a cornfield, dead players will come back to life."

But that line could just as well have referred to iPhones and Android phones: "If you build wireless features such as Bluetooth and Wi-Fi into a hand-held computer, somebody's going to turn it into a remote control."

Or lots of somebodies. Today, app phones can control all kinds of toys, either from across the room or across the Internet: computers, home security cameras, home entertainment systems, cameras, toy cars, and toy helicopters. But a start-up called Orbotix had an idea for a remote-controlled toy that was simultaneously far simpler and more complex: a ball.

It's called the Sphero ($130), and it's just rolling in from China this week. If it hadn't been delayed and now back-ordered, it might have been one of the hottest tech gifts of this holiday season.

Orbotix calls the Sphero a "mixed reality game experience," but that's like calling a nuclear meltdown an "unrequested fission surplus." Let's be honest: It's a remote-controlled ball.

You stand in one place, tapping controls on the screen of your Android phone, iPhone, iPad, or iPod Touch. The self-propelled, baseball-size sphere rolls around in the specified direction. You can't stop yourself from trying to guess how that's even possible.

There's a lot of advanced miniature technology inside: a tilt sensor, compass, gyroscope, and a little motor with wheels that makes the thing roll.

From the outside, though, all you see is a whitish translucent hard plastic ball. It has LED lights inside whose color, intriguingly, you can change using the Sphero app on your phone. They cast a strange, fish-shaped shadow on the top of the ball -- the shadow of the moving parts inside.

Before you get started with your freakish new remote-control toy, you have to prepare. Using your phone, you have to download the Sphero control apps from the Apple or Android app store.

Next, you charge the Sphero's battery, which takes three hours and yields an hour of ball-driving excitement. And where do you plug a charger into a featureless white orb? You don't. You simply set the Sphero down on its charging stand, which is itself plugged into a power outlet. The stand uses magnetic induction -- wireless charging -- to rejuice the battery. A very slick trick.

You give the ball a couple of shakes to wake it up. Now, in your phone's settings, you "pair" your ball to your phone -- a one-time Bluetooth ritual that ensures that only your phone controls only your Sphero.

On your phone, you now open the Sphero app. A series of tutorial screens walk you through orienting the ball -- teaching it which way is forward. You do this by twisting two fingers on the phone's screen. As you twist, a weird, glowing blue dot, shining from within, moves around the ball's equator. When it's pointing right at you, you're ready to drive.

You'll get very familiar with this orientation process -- you have to do it again every time the ball shuts itself off to conserve battery power, which happens after five minutes of inactivity.

There are actually five different free apps to install so far -- and, according to Orbotix, that's only the beginning. It has released a software-development kit that lets other people write new apps that make the Sphero do new, as yet unimagined things.

For now, though, here's what the apps do:

SPHERO: You drag your finger around inside a big circle on the screen. The ball instantly rolls in the corresponding direction; your finger's distance from center controls the speed. A Boost button causes the ball to make an extra vigorous thrust -- ideal for getting unstuck from carpet pile or cords trailing across the floor.

There's also a link here to Sphero World, which, at the moment, is nothing but a screen showing four cumulative statistics for your ball: Distance Traveled, Drive Time, Boosts, and Color Changes. The company says that this site will one day show things like your game scores and standings in competitions with other Sphero owners.

SPHERO DRIVE: This app offers two more ways to drive: one where you push forward/back and left/right levers on the screen, as on a traditional radio-controlled car remote, and another that lets you drive the ball by tilting the phone.

DRAW & DRIVE: Crazy clever fun. You draw a path on the phone's screen: shapes, zigzags, cursive words, your logo. Once you lift your finger, the ball follows that exact path on the floor. Well, "exact" might not be the right term; the distances are somewhat approximate. For example, if you draw a circle, the ball doesn't necessarily return precisely to its starting point. Note too that you can't make the Sphero stop and then reverse it; it can only change direction by rolling in a big arc, which adds to its feeling of mushy response.

You can use different colored "inks" in your drawing to indicate what colored lights you want the Sphero to turn on for that portion of its path.

GOLF: This app hints at the gaming possibilities for the Sphero. You aim the Sphero toward the "hole" of your "golf course" (for example, a pillow), and then "hit" the ball by flicking your finger on the screen or swinging the phone itself. You can even choose one of three clubs.

SPHERO CAM: Don't get excited -- there's no camera in the Sphero. Instead, this app gives you the usual driving controls but turns on your phone's camera, so you can make a video or a still of your ball on the floor.

And why would you want to do that? Because of the Sphero's screaming success as a cat or dog toy. Unless you have an especially blase pet, Sphero is pure baffling catnip (or dognip). The Cam app seems to exist solely so that you can record your critter's hilarious predatory responses to this colorful, rolling piece of plastic prey. (After all, when you're using the other apps, you can't use your phone's camera.)

None of these apps comes with instructions. The company agrees that they could really use some, and is working on it; a number of the options are fairly baffling.

Now, the Sphero is an amazing engineering stunt, and its novelty value is off the charts -- at least for the first day or so.

The huge problem, of course, is that the Sphero doesn't do anything but roll around and change colors. The company has bent over backward to spice up those two simple talents -- for example, those colorful lights inside mean that the Sphero looks really cool in the dark (nighttime Sphero Golf, anyone?). And the Sphero ball is waterproof; you can drive it right into the pool, for literally seconds of fun.

There's always the possibility that new apps written by other people will unlock new realms of family entertainment. Already, for example, the company's Web site heralds the coming of Sphero Blox, a timeline app that lets you drag command blocks into a sequence (drive, turn, change speed, change color) and then watch as the ball executes them.

Otherwise, though, $130 is an enormous sum to pay for a remote-controlled ball, even if it is the world's first and only. If the world's app writers come through, the Sphero might indeed one day become a "mixed reality game experience." Until then, it's a terrific technology demo that risks rolling all too soon into the back of your gadget drawer.