The Map Monster converts a spreadsheet of addresses into a Google Map with placemarkers in seconds!
It is a PHP program that I wrote during the weekend.
It does the following:
Grabs a list of addresses from a Google Spreadsheet and loads them as variables in PHP
Geocodes the address through the Google Geocoding API
Creates a Google map with the addresses marked as placemarkers.
You can find the program here: www.TheMapMonster.com