The Store Locator plugin for WordPress empowers web developers & web site owners to easily manage and display any set of important stores, products, or other locations on their website in an easily searchable manner. Uses Google Maps.
Download Link: http://downloads.wordpress.org/plugin/store-locator.zip
Home Page: http://www.viadat.com/store-locator
Wordpress Plugin Directory: http://wordpress.org/extend/plugins/store-locator