What is a participatory archive?

ArchivesNext raised a number of interesting points about the nature of participation in a participatory archive in a thought provoking blog post on building participatory archives. A somewhat typical emphasis in the discussion has been the novelty of letting 'ordinary' people in to have a say. The participation may be and has been suggested to be more or less radical from a rather controlled efforts to basically uncontrolled ones. ArchivesNext raises an important issue, I think, by underlining the role of an archivist as a participant. Participation is very limited if it is conceived as letting some others to play with (some of) my toys in my sandbox and not reaching out for the toys of other people in their own sandboxes. The same emphasis of reciprocity might be extended to institutions 8or archives within institutions) and considering how an archive might participate and be an active, perhaps actively radical and radically active participant in their traditional and non-traditional contexts.