Google Maps for Wordpress
The Google Maps for WordPress plugin allows you to easily insert Google maps into your blog, making use of the new shortCode system in WordPress 2.5. The maps can be configured to offer directions to or from the location, show or hide the zoom/pan controls, show/hide map type, activate zoom using mouse wheel, and more.
It requires a Google Maps API key, and then gives you a nice interface near your editor to help you build the map and send it to the editor.