I'm a big fan of using Google Spreadsheets as the back-end for Google Maps mashups. The Google Spreadsheet Wizard is a great way for non-programmers to easily create a Google Map that can be updated just by adding data to a spreadsheet.
MapAList is a new mapping service that also has a very simple wizard which will allow anyone to create a map from a Google Spreadsheet. What's more MapAList vastly improves on Google's own wizard by providing a great geocoding service.
Google's wizard requires users to find the latitude and longitudes of their markers whereas MapAList have developed a very accurate geocoder. MapAList utilises multiple international geocoders from Yahoo, Google and MapQuest so when users enter a named location MapAList will be able to find the latitude and longitude automatically. At the moment MapAList supports the geocoding of 6000 points.
Once a MapAList map is configured and created, any updates to the source spreadsheet are automatically applied to the map. MapAlist also allows unique map configuration options, such as the ability to group per column values, create queries and assign unique pin images.
Finally MapAList allows users to manage their maps in a number of ways. Users can make their maps private so that they are only visible on the user's own site or they can produce an embed code and share the maps anywhere.
Here are just two examples of maps users have created with MapAList: