My friend Andy launched a successful business in college, wrote a number of bestsellers in his twenties and thirties, and entered the worlds of philanthropy, investing, and politics in his forties. Life, for Andy, has been good--but apparently not good enough, for like many others, Andy seeks not just 50, 60, 70, or even 105 fascinating years on earth. He wants to live forever. His reasons range from wanting to see what happens next, to personal mountains not yet scaled, to a fondness, not yet sated, for TV.

Someplace short of eternal life is an online virtual world called Second Life, which sprang from the mind of entrepreneur and engineer Philip Rosedale, our cover subject this month. Anyone can enter this world: Businesses can market their wares and services and regular folks can create their own personas, or avatars, who fly around and engage in commerce and camaraderie with other "residents." Although this world is mainly fanciful, it also has areas devoted to the darker sides (parents beware!), meaning that Second Life bears some resemblance to the real world.

I wonder whether Second Life could eventually end up offering a kind of weird immortality. Perhaps in the not so distant future, sophisticated technology will permit people like Andy to create an avatar that will be able to chat with fellow Second Lifers, buy real estate, and listen to the latest music--forever. Hard to say whether this is the stuff of science fiction or just science.

The cover story begins here. For more thoughts on the future, check out our Guest Speaker column, this month written by entrepreneur and inventor Ray Kurzweil.

Jane Berentson