This report was developed from an invited talk I gave for the Research Squared Conference 2011 on Data Analysis held at the University of Loughborough. It examines the role of video within qualitative empirical studies of social conduct and organisation. I focus particularly on the use of video in ethnographies of technology use (mainly because this is my area of interest), and attempt to communicate why video is used to study social interaction. The report provides a broad overview of a particular kind of video use found in various different ethnographic traditions, and particularly focuses on instances within the fields of human-computer interaction, and computer supported cooperative work (e.g., workplace ethnographies of coordination and collaboration around technological environments). I’ll look at how video is used, practically, and what techniques and procedures are often employed. We will also cover briefly some underlying commitments to ethnomethodological or conversation analytic approaches that pervade studies of this kind. Finally I’ll look at what kind of findings you get from using it by covering a number of well-known studies which used video extensively, and consider what kind things you should be aware of when using video, such as various practical matters, caveats, and so on.