Matt- While their submission deadlines are well past, these are major conferences that will have fairly large numbers of papers/panels dealing with online issues. AAPOR (American Association for Public Opinion Research) May 15-18 in New Orleans http://aapor.org/2008annualaaporconference ICA (International Communication Association) May 22-26, Montreal, Quebec, Canada http://www.icahdq.org/conferences/2008/2008confinfo.asp