Big groups, little groups, family groups, workgroups, peer groups, hobbyist groups, political groups, sex groups, and all varieties of special interest groups – cyberspace is chock full of them. In fact, the potential for creating online groups is orders of magnitude beyond anything we have ever seen in the physical world. It is an important feature of how cyberspace accelerates social phenomena. This fact captures our attention and concern because groups are powerful forces. Beginning with such books as Rheingold's The Virtual Community (1993), researchers have described how gatherings of people in cyberspace take on the look and feel of groups in the real world. Being more skeptical, as suggested by the title of Weinberger's Small Pieces Loosely Joined (2008), we might wonder whether a truly cohesive, purposeful “community” in cyberspace is more of an illusion than a reality. In this chapter, I address that question by taking you on a journey through the online groups my students and I have studied during two decades of participant-observation field research, pointing out the lessons we learned along the way.