Nominatim's service is used for geocoding location searches.
A configurable lightbox with EXIF and GPS mapping support that works with native Wordpress galleries and images.
Geotag your posts with Bloom to create a local search and mapping visuals for your readers.
The most comprehensive & user-friendly mapping solution for WordPress
The easiest tool available for creating geo-tagged photo galleries. Display photos & their geographic location in a great-looking slider gallery
Allows Domain Mapping for WordPress MU (sub-domain and sub-directory installations).
The easiest tool available for creating custom & great-looking Google Maps. Add multiple pins and customize maps with drag-and-drop simplicity.
The Pronamic Domain Mapping plugin allows you to map domains to custom domain name pages.
Add maps to your posts or pages, embed Microformat Geo or Adr, and output GeoRSS and KML.
Sorry, discontinued
Enhance the look and feel of GEO my WP's "Current location" widget/shortcode form. Easily modify or create you own forms to improve user's experience.
This plugin supports multiple markers per map! Kudos to yohman for his plugin:
http://wordpress.org/extend/plugins/google-maps-v3-shortcode/
Introducing a unique and ultra-modern location management system that lets you add a Location Finder option directly to your site.
This plugin allows you to add one or more maps (via the Google Maps v3 API) to your page/post using shortcodes.
Serves a specific page or post from WordPress depending on the domain used to access your WordPress site.
Quickly transfer structured content to and from your GatherContent projects and your WordPress site.
Map My Posts allows you to display a Google Map or Geochart visualization, associating map locations with your existing categories or tags.
Add incredibly powerful Google Maps with Mapify Lite: Custom image mode, tooltips, per-location photo/video galleries, & more!
MapJam is a personalized mapping platform giving individuals and organizations the easiest way to personalize and share maps!