Early virtual worlds such as ­Second Life demonstrate that highly visual, 3-D online environments hold the potential to transform the way humans interact not only with computers but with each other (see "Second Earth"). Hyped as they are, these immersive environments address two fundamental aspects of being human: our visual and social natures.

To make these platforms ­viable for business and consumer uses other than Second Life, the technology and business communities must begin collaborating now, because significant challenges lie ahead.