For Greg Hahn, a self-described eavesdropping addict, being nosy isn't just a hobby. It's the weapon that has allowed the master copywriter to consistently lend human voices and emotions to huge corporations such as Citigroup (the "Live Richly" campaign for Citibank), eBay (the "It" ads), and Mars (the "Caramel Stretch" campaign for Milky Way). But Hahn's most lyrical branding effort involved no words at all. For client HBO, he and his team conceived an elaborate digital diorama of a New York apartment building. With only visuals to tell the story, 12 interwoven plotlines unfolded online -- and were projected onto the side of a Lower East Side building -- in real-time. It drew more than 1.2 million viewers and won numerous awards last year. Its name, fittingly for Hahn, was "HBO Voyeur." -- by Danielle Sacks