In this paper I identify some current elaborations on the theme of participation and digital literacy in order to open further debate on the relationship between interaction, collaboration and learning in online environments. Motivated by an interest in using new technologies in the context of formal learning (Merchant, 2009), I draw on in-school and out-of-school work in Web 2.0 spaces. This work is inflected by the new literacies approach (Lankshear & Knobel, 2006a). Here I provide an overview of the ways in which learning through participation is characterised by those adopting this and other related perspectives. I include a critical examination of the idea of "participatory" culture as articulated in the field of media studies, focusing particularly on the influential work of Jenkins (2006a; 2006b). In order to draw these threads together around conceptualizations of learning, I summarise ways in which participation is described in the literature on socially-situated cognition. This is used to generate some tentative suggestions about how learning and literacy in Web 2.0 spaces might be envisioned and how ideas about participation might inform curriculum planning and design. (Contains 3 figures.)