Population > 4.2 million
Leading indicator > No. 1 in the world in scientist citations
Fast companies > Lucasfilm; Wild Brain; and nearby, the whole Silicon Valley crowd
Is there a more continuously creative city in the world? The epicenter of U.S. entrepreneurship is still tied to Silicon Valley's fortunes, but it's also hatching its own digital-media sector and a biotech and biomedical hub around UCSF.