Here is a form that can be used to generate the API code needed for Google Maps. The purpose of this tool is to allow you to place in certain parameters and get back the code to place a map on your page. (A Google Maps API key is required)
Here is a cool little tool if you are using Google Earth. This user has created a PHP script to make the conversion from Google Maps to Google Earth. Here are the instructions taken from the following page:
#1: In Google Maps: Double-left-click inside the map/satellite view to center where you want and generate the correct link (Rem: to forget this #1 may drive you to the west coast of Africa...).
#2: In Google Maps: Copy the link behind "Link to this page" (top right of the screen)
#3: Paste it here
#4: Give it a name if you wish (optional)
#5: Hit "GO" to get the KML File that you can open in Google Earth or saveGive it a try!
(The script's creator has also created more than 100 Google Earth placemarks for the Principality of Monaco if you're interested.)
Hopefully these tools will be helpful for folks out there using Google Maps and Google Earth, as well as those creating the next big Google Maps mashup!