NCGIA turned 20 years oldon December 1 2008. The anniversary was celebrated with a conference in Santa Barbara California on December 11-12 2008. Over 50 former NCGIA researchers, Board members, graduate students and initative participants attended the meeting. Part of the meeting was a retrospective on NCGIA contributions to GIScience but the bulk of the meeting was devoted to idenitifying new research challenges in GIScience. Meeting presentations are available from http://ncgia.ucsb.edu/projects/isgis/participants-isgis.php