This paper considers the relationship between depth of participation (i.e., the effort and resources invested in participation) versus (tangible) outcomes. The discussion is based on experiences from six participatory research projects of different sizes and durations all taking place within a two year period and all aiming to develop new digital technologies to address an identified social need. The paper asks the fundamental question: how much participation is enough? That is, it challenges the notion that more participation is necessarily better, and, by using the experience of these six projects, it asks whether a more light touch or 'lean' participatory process can still achieve good outcomes, but at reduced cost. The paper concludes that participatory design researchers could consider 'agile' principles from the software development field as one way to streamline participatory processes.