He didn't "invent" the Internet, but Al Gore played a key role in moving a military data communications network called Arpanet into the commercial realm. The rest is history. Gore has since moved beyond a turbulent political career to become the planet's spokesman on climate change. Along the way he picked up an Oscar (Best Documentary, for "An Inconvenient Truth") and the Nobel Peace Prize.When not campaigning against greenhouse gases, Gore has built a considerable business empire based largely on extensive contacts in Silicon Valley, particularly among venture capitalists along Palo Alto's Sand Hill Road. On Jan. 28, he announced that his interactive cable TV company, Current Media, plans to raise as much as $100 million in an IPO on the Nasdaq. Underwriters led by JPMorgan and Lehman Brothers are reportedly preparing a prospectus. The proposed launch brings Gore full circle, back to the merger of conventional media and the Internet. Gore didn't invent the Internet, but he seems determined to reinvent it.By George Leopold