by Maximilian Ruthe on WordPress.org
WordPress Google Maps plugin with automatic single/multi address marker display via custom meta & shortcode.

Snapshot of Restaurant Girl with auto map display from archive posts.
Automatically display Google Maps with multiple location markers in your category/archive or single marker maps on single pages via addresses from custom fields on posts or custom post types.
You can now preview the map from the add/edit screens of corresponding post types.
Display your Google Map anywhere using the [map] shortcode and choose a default address if not address is found in content from the plugin options, or simply type one using address, for example: [map address=”Mountain View, CA”].
Choose Auto Map Marker creation from plugin settings, choose posts, pages and/or any custom post types and custom fields you want to use.