But in 2005, alternative, or renewable, energy vaulted the highly fortified border separating cottage industry and big business. With oil and gas prices soaring, the allure of alternate energy sources is apparent.

Veteran analysts of investment manias might detect eerie similarities to an era many would just as soon forget: the 1990s dot-com boom. Is a new bubble in the offing?

Let's go to the handy bubble checklist.

Hot initial public offerings? Check.

Some of the IPOs most in demand recently have been of solar energy companies. Shares of SunPower, for example, rose 41 percent on the first day of trading this fall.

Enthusiastic venture capitalists? Check.

"In 2005, we saw a tripling of venture capital money going into the solar industry compared to 2004," said Rhone Resch, president of the Solar Energy Industries Association.

Old-line companies talking the talk? Check.

In the 1990s, blue-chip companies added adjectives like interactive to the corporate lexicon. Today on General Electric's Web site, the company's chief executive, Jeff Immelt, rhapsodizes about renewables.

Government policy adding a helping hand? Check.

In the 1990s, the government appropriated taxpayer cash to build a high-speed broadband infrastructure. Today, it's subsidizing the installation of solar panels through tax credits.

New buzzwords? Check.

In the 1990s, magazines like Red Herring championed the dot-com boom. Today, Red Herring is pushing "clean tech."

Visionary entrepreneurs bent on changing the world? Check.

Bill Gross founded IdeaLab, which spawned Internet businesses that aimed to change the world. Today, he's backing Energy Innovations, which aims to build low-cost solar arrays. If his products can reduce the cost sufficiently, Gross told Red Herring, "then we will change the world."

Breathless Wall Street analysts? Check.

"This is not just the most attractive space in the energy sector, but probably the most attractive space across equity markets, period," Michael Rogol, global solar market analyst for CLSA Asia Pacific Markets, told The Wall Street Journal. — Daniel Gross

CHINA — THE N-PROBLEM AND OUR PAL BEIJING

Consumed by its response to 9/11, the Bush administration rarely focused on China in its first term. Now "later" has arrived.

The biggest test of Washington-Beijing realpolitik in 2006 may be North Korea and Iran. For the first time, the White House finds itself deeply dependent on the active help of China's leaders. If it has any hope of stopping the nuclear programs in Pyongyang and Tehran, it needs Beijing's leverage. Unfortunately for Bush, the interests of China and the United States are quite different.