Integrate a Rectifier to be able to overlay Old Printed Maps on the base maps:
 * [wiki:UserGuidelinesGISData#OldPrintedMaps]

Design discussion for !GeoExplorer:
 * http://projects.opengeo.org/geoext/wiki/Georeferencing

----
[wiki:BluePrintGeographicInformationSystems GIS BluePrints]