Measuring Distance
World Mapper - skewed maps based on data - http://www.sasi.group.shef.ac.uk/worldmapper/index.html
How Far is It? http://www.indo.com/distance/
City Distance Tool - http://www.geobytes.com/CityDistanceTool.htm?loadpage
Latitude and Longitude LookUp - http://www.spreadsheetconverter.com/samples/shortest_distance.xls - spreadsheet that calculates distances or http://www.spreadsheetconverter.com/samples/shortest_distance.htm
How Do You Calculate the Distance Between Points? - free tool for ArcMap - http://www.urban-research.info/ur/GIS%20Skill%20Builder-distance1.shtml (Comments at http://groups.google.com/group/comp.soft-sys.gis.esri/browse_thread/thread/a08eda6d062a5109/3ebdd4fd5c629e19)
Great Circle Calculator - http://williams.best.vwh.net/gccalc.htm
ESRI - Measuring distance between points forum discussion - http://forums.esri.com/Thread.asp?c=93&f=995&t=91074#441100
Spider diagrams in ARcView
Script or Hawth's tool possibility - http://forums.esri.com/Thread.asp?c=93&f=982&t=193451#575225