A few years ago, Dan Chudnov summarized his mission as a librarian in one simple statement: “Help people build their own libraries.” I think this statement summarizes nicely my research interests into social discovery tools. For the past five years or so, I’ve been arguing that library catalogues need to be more dynamic and have the potential to be an environment where people can interact with each other and library staff, and discuss and share their reading, listening, viewing, etc., interests, via social tools such as tagging and posting reviews. Social discovery tools have the potential to foster a sense of community amongst library clients. My local public library serves clients that are scattered over a municipality that includes urban, suburban, and rural areas. Not all residents of this municipality are fortunate enough to have easy and close access to a library branch; a number of these residents cannot visit easily their local library because of health, limited mobility, lack of available and convenient transportation, and so forth. From a cataloguing perspective, client tags allow me to determine the extent to which my assigned LC headings reflect the language of the client, as well as their perception of the content of the item. Tags can not only complement the descriptions offered by the LC subject headings, but allow the expression of the the different cultural perspectives of the community, which is particularly important in Canada, where cultural pluarity is an essential and encouraged aspect of our society.