Distance between... and other map questions

How far is it? (calculates distance between cities, zip codes, latitude/longitude; includes 500 cities around the world as well as US locations)

an algorithm for lat/long distance calculation using a hand calculator with 'degrees' option

distance between major French cities from France Telecom

Great Circle distance calculator beyween US cities' airports with hard-surface runways

World Map from Xerox PARC (no distance calculation, but handy for basic outlines)

A very cool article on Geographic Information Retrieval and Spatial Browsing by Ray Larson of UC Berkeley