The folks at Wotton.org have put up a simple online app that makes it easy to put up a Store Locator for your website in no time with Google Maps. The advantage of showing it in an online map is that it can utilize the Driving directions feature that can be useful to visitors of that website.
The app provides a simplified UI to build a KML file. It takes coordinates of the locations, with any titles and description that you may want to add. A KML (Keyhole Markup Language) file is basically a standardized XML schema file that can hold geographic coordinates & related content.
You have to drop this KML file in the same directory as the web page in which you want to show the map. A template HTML file that contains the Javascript to merge the KML/XML file info on the map, is also provided.
Google Maps runs only when you have an API key registered for your website. So you need to sign up for it (for free).
Each API key is uniquely mapped to the directory (URL) where the web page with the embedded map is used. So you cannot use somebody else's API key or use your own on a different domain than what you have registered with. If you try it, it throws this warning - The Google Maps API key used on this web site was registered for a different web site. You can generate a new key for this web site at http://code.google.com/apis/maps/
Thanks Jeffrey for sharing this tip.
Related link -
Road/Street maps of Indian cities on the Web