Conducting Usability Studies at User Group Meetings 
In this day and age, getting closer to your user base is imperative for creating user-centric documentation. This paper discusses how the Technical Publications group at Mentor Graphics tapped into their annual User Group meeting (MUG) to conduct usability studies. We cover: Convincing management of the ROI of participating in the User Group meeting; establishing relationships with meeting organizers; defining proper "protocol" for interacting with users and other meeting attendees; planning for and dealing with equipment setup; recruiting users to the usability lab; considering and acquiring incentives for usability lab participants.
Yaspo, Catherine and Sarah E. Leritz-Higgins. STC Proceedings (2005). Articles>Usability>Testing>User Centered Design