Weblogs have recently emerged as a popular means of sharing information on the Web. While they effectively foster the networking of participants on a one-to-one basis, so far they have been lacking the capacity of allowing the establishment of many-to-many communication relationships. This paper describes recent work on facilitating group-forming processes and the sharing of content among weblog authors with shared interests. We have designed, implemented and tested the Internet Topic Exchange, a system that enables weblog posts to be shared among open groups in the form that we call topic channels. After nearly a year of operation, more than 200 topic channels have been created; several of them have been very active and have brought together many participants. This suggests that our approach to enabling weblog authors and topical content to cluster while retaining the advantages of personal publishing is a viable one.