Kimberle Koile Konrad Tollmar David Demirdjian Howard E. Shrobe Trevor Darrell Activity Zones for Context-Aware Computing. 90-106 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2864&spage=90 2003 conf/huc/2003 Ubicomp db/conf/huc/ubicomp2003.html#KoileTDSD03