For some time, I've been wanting to create a video podcast site and see if I could get a community going around it. Based on things I've learned from blogging bootcamps and dealing with consulting clients, I'm convinced most successful communities have to have some real world basis. It's not that purely online communities cannot thrive, it's just that they tend to be composed of true topic devotees who are also facile with computers and use them as a principal means of accessing information. That tends to limit the possibilities of what can work.
By the way, by community, I don't just mean site visitors but rather people who are aware of each other and care what each other is doing. So, I'm not just talking about pulling in readers with adwords and getting them to convert.
So, what we have done is put together a site called Muscle Ventures. It offers text content, exercise analysis videos, and podcasts. The site seems to be working for the local community. We'll see what we can do for the Internet community. I'll be writing more on this topic as the situation evolves.

I am one voice in search of such a community. I have a vison of a subject based community which would host audio and video and provide a communication hub. My interests lie in geopolitical policy mainly, but culture, technology, and society are at the core.
I have always been more of a message board type of person and have coexisted with thousands of regular visitors to the Something Awful forums for several years.