PHP Class for Building Maps using Google Maps API
Brad Wedell has updated Monte Ohrt's popular PHP class for building Google Maps to use the latest v3 of the Google Maps APIs. The intent of this PHP class is to make it easier for developers to quickly and easily integrate a map into a web page with very little effort.
Atlas Plugin API and MapKit
Cappuccino is an open source application framework for developing applications that act like desktop programs. The new Cappuccino Atlas Beta includes a sample plugin for the Google Maps API.
Digitalspaghetti's jQuery Google Maps Plug-in
jMaps is a jQuery plugin that provides an easy API to create and manage multiple Google Maps on any page. Hosted on github.
Speckyboy also has a nice round-up of ten jQuery plug-ins for Google Maps.
Google Maps Store Locator Plugin for Wordpress
Viadat have produced a Google Maps Store Locator plugin for Wordpress. The plugin enables you to create sites in Wordpress to show the locations of stores and points of interest.
The plugin allows users to import locations from CSV files and can export locations to CSV and XML for safe storage. The plugin also supports a number of themes so that you can customise the design to suit your website.
XML Google Maps Wordpress Plugin
This plugin allows you to easily insert a Google Map or Google Earth browser map into your WordPress blog. You just have to add a link to your self defined Map from My Google Maps, Picasa Webalbum Picture Map, any geoRSS Feed (like Flickr), your uploaded Google Earth file (kmz, kml) or any other dynamic or static Google Earth file (umapper.com, flickr.com, etc.).
LatLonGeeks Google Maps Forum
Yordan Yordanov has created a forum for map developers to discuss the Google Maps API. Users can also use the forum to discuss Map API's.