[kaushik_]

Not really. ask.fm is a random ask and answer but ama-live.com has different rooms to ask different people and have ama sessions for an hour or so. Reddit - I use it a lot but I think its much of a discussion board, its not meant for AMAs in particular. Too much nested commenting creates noise and its usage is not simple. Plus the discussion is controlled by moderators of the subreddit which is not a good way of doing an AMA. My two cents.