As arguably the fastest-growing online social network, Facebook is exerting considerable influence on the evolution of the Web today especially in how individuals engage with each other. For associations, "the Facebook effect" is a direct challenge to our community's traditional thinking about the meaning, substance and experience of membership. Associations have a great opportunity to embrace this fresh approach and use the compelling ideas these technologies provide. Explore the emergence of social networks overall, the specific impact of Facebook and the powerful new possibilities for association membership created by the still-unfolding social network phenomenon.