David Sacks is an internet businessmen. He rose to fame as the Chief Operating Officer of PayPal from 1999-2000. After leaving PayPal, Sacks made a foray into the film industry and produced the Golden Globe nominated movie Thank You For Smoking. In 2006, Sacks founded the genealogy focused website Geni.com. Sacks went on to launch the microblogging site Yammer which won TechCrunch50 "Best in Show" in 2008.
Yammer
Yammer is a business microblogging site that allows users to communicate with one another, form groups, upload attachments and track projects. The system is compatible with most smart phones, including the BlackBerry and iPhone.
Geni
Geni.com is a website that allows users to create family trees online. These trees, filled with contact information of the participants, allow for a robust social network of relatives and help distant family members connect with one another.