Last updated Jan 2018
This tool allows you to create a KML rectangle or grid mesh covering a desired area. When the KML file has been created you are given the option for it to be automatically opened in Google Earth.
The latest version of this tool also has a "Make tiles" button which generates xml files to help with generating custom HandyGPS offline map tiles.
You can also generate a circle or an arc.
An example of a generated grid mesh