Despite significant growth in public participation GIS (PPGIS) literature since the 1990s, little engagement by e-government scholars is evident in the extensive scholarly PPGIS debates. To fill this void, recent trends in PPGIS adoption by local governments are analyzed. Three waves of GIS are identified: desktop GIS, web GIS, and the Geospatial Web 2.0 platform. Such technological advancements have progressively eased GIS accessibility from expert users to ordinary citizens, accompanied by considerable growth in adopting PPGIS for traffic and transit, volunteered geographic information, and customer relationship management. However, limited use of PPGIS for higher levels of participation such as decision making is found. Barriers to PPGIS adoption for decision making seem less technological and more institutional.