Pennsylvania Department of Environmental Protection (DEP)
http://www.dep.state.pa.us/

MapQuest
http://www.mapquest.com/

TerraServer
http://www.terraserver.com/

USGS - U.S. Geological Survey
http://www.usgs.gov/

PASDA - Pennsylvania Spatial Data Access
http://www.pasda.psu.edu/

AutoCAD
http://www3.autodesk.com/adsk/section/0,,284288-123112,00.html

Lancaster County Resource
http://www.co.lancaster.pa.us/

Weather Channel
http://www.weather.com/

Pennsylvania One Call System, Inc.
http://www.paonecall.org/

Tyndale Car Wash Systems, Inc.
http://www.tyncom.com/