One of the benefits of an API is that people can add the features you forgot to build. Case in point: ACME Mapper. They’ve taken Google Maps and added a scale indicator (miles and kilometers), quick find, lat/long display, print button, link-to-this-map button, additional US imagery from the USGS, and lots of US geocoding built right into the map. Very nice, even though the UI looks very 1994 Motif Toolkit. See my home and the O’Reilly campus (and the then go back in time) as an example. Another site extending Google Maps, though I found the features less useful, is Power Map, which lets you click around and see distance, go to specific lat/long, save and restore waypoints, etc.
