This article explores how information technology affects the forms and possibilities of voluntary efforts. Specifically, the authors examine the emergence of grassroots organizations in cyberspace. An analysis of two cyber-grassroots organizations (CGOs), Afghanistan Online and Rebuild-Afghanistan, highlights CGOs’ similarities, differences,and relative strengths and weaknesses compared to their traditional physical-space counterparts. The article concludes with a discussion of the implications for our understanding of grassroots organizations generally. Traditional characteristics such as size, scope, and the nature of communication need to be refined to better account for new forms of grassroots organizations.