SAN FRANCISCO -- Imagine being able to control your computer and manipulate on-screen objects not with a mouse, keyboard or even your voice, but with a wave of your hand.
Now meet what makes it possible: the Leap Motion Controller, an $80 device that's already responsible for at least 73,600 online references to the Steven Spielberg-Tom Cruise movie "Minority Report."
The controller, which is about the size of a pack of gum, connects to your Windows PC or Apple Mac via a USB cable. Sensors on its top create an invisible bubble about two feet around, within which your hands' motions and gestures are sensed and translated into actions on the screen.
This being new technology, you shouldn't expect a polished user experience, and indeed I encountered a number of hiccups. But early adopters willing to put up with its quirks can have some fun.
Using the controller and special Leap Motion-enabled apps, I was able to virtually dissect a frog simply by moving my hands. I was also able to page through a selection of New York Times stories, play drums and soar around the Earth at hyperspeed, all without touching the computer.
It took me a while to get the hang of controlling the screen with my hands, but once I did I found the Leap Motion device swift and sensitive. There was no discernible lag time in interpreting my gestures, and it could distinguish not just my hands but individual fingers.
The Leap Motion unit is a cousin to Microsoft's Kinect, the motion controller first introduced for the Xbox game console and now available for Windows PCs too. But the much-larger Kinect is designed for whole-body sensing, while the Leap Motion is intended for close-in work focusing solely on your hands.
Installation took about five minutes, and couldn't have been much simpler. Once I connected the unit -- Leap Motion thoughtfully provides two cables, one long and the other short -- I downloaded the software and was ready to go.
Or would have been, except that the 2009-vintage machines I installed it on, a Windows PC and MacBook Pro, proved insufficient. Only up-to-date hardware is powerful enough to make use of the controller: at a minimum, an Intel Core i3 or AMD Phenom II processor, Windows 7 or 8 for Microsoft-powered PCs and Snow Leopard for Macs.
I was able to install it successfully on two more recent Macs and a Windows PC, all with i5 processors. But I ran into other issues as well.
Sometimes, things on the screen would bounce around even when my hands were still; the company says that might have been caused by the amount or type of ambient lighting. (Among other things, halogen bulbs can cause interference, and a light located directly above the sensor can confuse it.)
In addition, Leap Motion's digital-rights management scheme made my Symantec Internet-security program go nuts; the company says it's working with anti-virus companies to get their programs updated to recognize that its software poses no threat.
Initially, at least, most users will probably take advantage of the Leap Motion's capabilities through dedicated apps downloaded from its online marketplace, called Airspace. About 75 are available at launch, in categories ranging from games to productivity.
These early apps vary widely in quality as well as price, and many of them seem more designed to show off the sensor's capabilities than to perform useful functions. The Times app, for instance, displays only a handful of stories; you page through them with your hand, select one by hovering over it and scroll up and down by rotating your finger.
If the technology catches on, you can also expect to see motion control built into existing software. It's already, for instance, supported in the Google Earth satellite-imagery virtual-globe program.
The Leap Motion technology has stirred a great deal of interest in the tech community. At launch, the controller is being sold at Best Buy stores in the United States and from Amazon.com's British site, while PC makers Hewlett-Packard and Asus have also struck deals to bundle it with some of their models. (HP has plans to build the technology directly into some machines as well.)
For now, it's a work in progress, one whose transformative power is more theoretical than real. Still, it provides a fascinating glimpse into one potential future.
Come to think of it, wasn't that the plot of "Minority Report?"