Both Google Maps and Earth have tons of useful (and engaging) functionality.  Not only can you get driving directions, but you can also make custom maps that include information and pictures about locations and then embed them in your own websites.  Google Earth has a great "fly in" that starts at the outer space view of the planet and then flies in to your location, zooming in as it goes.

Google Maps Ideas:

Travel Guide: If students are doing a project on local history, have them take on the role of travel agents and create an "attractions map" of their area.  They can use Google Maps to mark various interesting locations and include information they collect in the descriptions.  They can then publish their maps on a website that might include links to more information or local businesses.  A great way to interact with the community.  This one was created by a real tourism company and embedded in their website.

Virtual Vacation: Students can use Google Earth (download here) to virtually visit almost any place on Earth.  Studying Ancient Egypt?  Use Google Earth's 3D map to SEE the pyramids on the map.  A great way to teach geography, a great way to feel connected to the world.  Take it a step further and use Skype to actually contact a school in a place you have virtually visited.  21st Century pen pals!

Here is an example created by Heritage Key, a culture and history online community.  You may need to download the plugin to view it.

(Chelsea Sims - Teacher Librarian - Iowa)