"THWONK" is both a media artwork and a novel approach to designing online communication systems and communities. The idea for "THWONK" began with "BumpList" an email community art project I developed (along with Mike Bennett) while a Research Fellow at Media Lab Europe in Dublin, Ireland. BumpList launched in June 2003 as a gate page artwork for the Whitney Museum of American Art's "ArtPort" website (link: http://artport.whitney.org/gatepages/june03.shtml). Described as an ..email community for the determined," BumpList allowed a limited number of subscribers (only 6 people could subscribe to the list at any time) so that when the seventh person subscribed the first person in the queue was "bumped" or automatically unsubscribed from the list. Thus users would have to "re-subscribe" to re-join the list, in turn causing someone else to be unsubscribed, etc... This small, "musical chairs-like" exchange in the social rules and dynamics of online mailing lists created surprising results and experiences from users who went to great lengths to try to stay part of the community they were removed from so frequently. "THWONK" builds upon ideas introduced in BumpList by expanding the scope and domain of activity normally expected in online communication.