Webster's defines a valley as "a stretch of low lands between hills or mountains." But for a growing number of tech entrepreneurs and workers, "Silicon Valley" is a squared-off patch surrounded by water, not mountain ranges.
Consider this: San Francisco has led the world in venture capital funding for three years running, and the city has more than 4,000 startups in the South of Market area alone, according to San Francisco tech incubator the Hatchery.
Of course, the South Bay remains the home of Silicon Valley's dominant companies: Apple (AAPL), Google (GOOG), Oracle (ORCL) and Hewlett-Packard (HPQ). And the venture capital industry is still all but run from Sand Hill Road in Palo Alto.
