One of the students in the course that Xiao Qiang and I teach at Berkeley created this very fine blog about participatory video as one of her class projects:

Videovoice is an approach to participatory video that is rooted in the practices and conceptual frameworks of community-based participatory research (CBPR) and participatory media. As the graphic below depicts, these approaches to research and media have a number of common influences, such as critical theory, and disparate influences, such as new media theorists and the intellectual contributions of Paulo Freire.
<