Let Kleiner Perkins Caufield & Byers (KPCB) beware -- or, at the very least, be on the lookout. The venture capital firm invests money, time, and intellect in innovative early-stage companies that sometimes become the foundations for new industries. KPCB has invested in such notable outfits as AOL, Amazon, Genentech, Google, Groupon, Sun Microsystems, and Twitter. The firm focuses its energies on information technology, life sciences, social networking, iPhone and iPad applications (apps), and green technology investments. (Al Gore is one of its partners.) Since its inception in 1972, KPCB has invested in more than 500 companies; it has taken more than 150 of them public.