Crime Mapping News has a nice two-page writup on how the Santa Monica Police are using a GPS-enabled camera to keep track of graffiti abatement (see pages 2 & 3). The cameras (made by the company I work for, Ricoh) include a drop-down menu to tag images with meta-data, including things like gang affiliation associated with a particular graffiti tag. The images can then be downloaded wirelessly from any city Wi-Fi station and be viewed in aggregate along with other GIS information.