What 685 things have been seen by 225 million people, translated into 77 languages by volunteers and are available for free on You Tube? TED Talks! Here's an excellent and energetic presentation from Web 2.0 Expo where June Cohen explains how TED went from being a conference to a platform and more. What did they do? They listened, tried to reach people everywhere, embraced open models, and paid attention to the way users want to access content and delivered a good experience...and they have wonderful speakers!
Here's a story about the New Orleans with a mention of TEDx NOLA and the way ideas spread through the use of the TED platform.