The Irvine Spectrum rivals other high-tech areas in the United States. Here are comparisons:

5,000 acres, 2,500 companies, and 55,000 jobs, the 19-year-old business area has developed 40 million square feet to date.

Home to prestigious high-rises and campus-like environments, Irvine Spectrum is a world leader in its concentration of technology research, development and manufacturing companies.

Six technology industry clusters have emerged in Irvine Spectrum: Software, biotech, computer hardware/software, medical devices, broadband, and automotive design.

Some of Irvine Spectrum's leading companies include Broadcom, Verizon Wireless, Toshiba, Advanced Sterilization Products, Quest Software, Meade Instruments, Ford Motor Company's Premier Automotive Group, comprised of Volvo, Jaguar, Land Rover and Aston Martin.

1,500 square miles, 1.35 million jobs, the high-tech center of the world.

Software has the largest cluster of employment, followed by semiconductor and semiconductor equipment manufacturing. Employment in biomedical alone is more than 35,000.

Major companies include: eBay, Apple Computer, Sony Electronics, and Cisco Systems.

7,000 acres, more than 130 companies, more than 50,000 jobs.

The Durham, N.C. business park calls itself the largest planned research park in the United States, developed for corporate and governmental research.

Major companies and institutions include, or are associated with, GlaxoSmithKline and three doctoral research universities - Duke University in Durham, the University of North Carolina in Chapel Hill and North Carolina State University in Raleigh. Special state-supported groups such as the Microelectronics Center of North Carolina, the North Carolina Supercomputing Center and the North Carolina Biotechnology Center are located within the park. Others include the contract research organization Research Triangle Institute, the National Humanities Center, and the EPA's largest operation outside of Washington, D.C.

Comprised of the metropolitan area of Austin: 1,524 high-tech companies and 73,610 jobs.

Major companies include Dell Corp., of which 16,000 are employed; Motorola; and IBM.

Sources: The Irvine Co.; for
Silicon Valley, svmg.org and jointventure.com; Greater Durham Chamber of Commerce website, www.rtp.org/); for the tech center, the Greater Austin Chamber of Commerce.