For MapInfo users... Mapinfo2Google
Mapinfo2Google.mbx converts MapInfo map objects from one or more visible layers within a Mapinfo map window to a Google Earth KML file. Includes source code provided under GNU General Public License. Requires Mapinfo Pro ver 4.1 or later.

For the ESRI user... Arc2Earth
Convert your raster or vector datasets to KML or KMZ format. Arc2Earth will translate as much information as possible including Labeling, Renderers, Graphics and Layouts. Designed for users of ESRI's ArcMap cartographic authoring environment.

DIY Real Time GPS Tracker
You can create a real-time GPS tracker using Google Maps API. Don't worry about having a GPS device, you can emulate a garmin using GPSGate. Then later you purchase fancy gps devices and a JunxionBox

create Keyhole or Google Earth XML files
a nifty Keyhole hack that enables us to get surface altitude data. Simply import in coordinates, and when you export - the data is decorated with altitude data. the authors have alwso come up with a very slick GPS Camera prototype that combines a camera and GPS unit (see http://jrhicks.net/67).
http://jrhicks.net/95

Google Earth KML Tutorial
The Google Earth KML Document details everything you need to know to create and share information with the Google Earth client. If, however, you would like to jump right in and see some real examples of what you can do with KML, then this tutorial is for you.

Discussion paper - ArcGIS 9.2 Server Support for Keyhole Markup Language (KML)
Technical Paper discussion how at version 9.2, ArcGIS Server will allow publishing of GIS data in a format compatible with Keyhole Markup Language (KML) clients. -- See also this Google Earth KML Documentation.

FME Suite for Google Earth
When it comes to spatial data formats you know FME software is going to come up with a solution to help import or export your data! FME Suite for Google Earth is a FREE trial version of our industry leading spatial data conversion software that enables users to create KML files seamlessly from data stored in over 150 CAD, GIS, and Database formats.

3d tracking
3d tracking is a revolutionary way to use the Internet to either monitor the movements of a live vehicle/person or to display a previous route that's been travelled. The vehicle/person's path is displayed as a line on either Google Earth or Google Maps with details of the speed at each point along the route. This allows you to follow the progress of a live vehicle, watching the points appear on the map as the vehicle moves.

Google Maps KML Writer
KML Writer is a demonstration of how Google Maps API can be used to draw vector points, lines and polygons. The page uses JavaScript on the client side and ASP.NET on the server side.

Shape2Earth (SHP to Google Earth)
Shape2Earth requires Google Earth Version 3.0.0762, and MapWindow GIS Version 4.1.2342. A preliminary product enabling users to imports SHP data directly into G. Earth

Google SketchUp (free)
Google SketchUp (free) is an easy-to-learn 3D modeling program that enables you to explore the world in 3D. With just a few simple
tools, you can create 3D models of houses, sheds, decks, home additions, woodworking projects - even space ships. And once you've built your models, you can place them in Google Earth, post them to the 3D Warehouse, or print hard copies. View the resultinng 3D renders within Google Earth

SketchUp Google Earth Plugin
Install this plugin to give SketchUp the ability to read and write Google Earth model files in the *.kmz format, and take 2D and 3D snapshots from Google Earth. If you want to send 3D models from SketchUp to Google Earth, this is the place to start.

GIS-integrated 3D Landscape visualization - Scene Express
Scene Express now includes a new exporter for creating landscapes in KML/KMZ format for use in Google Earth or other KML-compliant applications like ESRI's ArcGIS Explorer or NASA's WorldWind. Export landcover textures including roads, orthophotos, foliage, 3D structures, water and other landscape elements from any WCS/VNS scene straight to Google Earth for viewing within an interactive 3D planet environment. Note: Scene Express 2 now supports Google Earth 4's new capabilities

G. Earth Mobile...

finally... for mobile enthusiasts one of my favorite apps!
PHONE2GEARTH
Phone2GEarth is a simple software for your Nokia S60 which allow you to store your gps positions and export them to the Kml google earth format. Just with a double click on the file, Google Earth will show you your last track.

also... Phone2GEarth for Nokia Series 60
Phone2Gearth converts GPS data directly to Google Earth® KML files. Phone2Gearth is an easy Nokia Series 60 GPS aplication that allows to log tracks which are directly saved as Google Earth KML files.

These are but a few of the cool add-ons, tools, and apps that the GISuser will enjoy integrating with google Earth and Google maps. For a great directory of some 100 related add ons and tools see our Google maps Masher / Mashup APIs section of our tools repository

An interesting application:

Down-under at the Victorian Rainforest Network (VRN), the crew is using Google Earth to help learn more about the rainforest and logging issues in a virtual 3D environment. This use clearly demonstrates the increased understanding of, and ease of access to, spatial information by non-spatial professionals resulting from the release of Google Earth.

Somewhat related weblinks:

• http://earth.google.com/ - Google Earth Home
• http://maps.google.com/  - Google Maps home
• http://sketchup.google.com/ - SketchUp
• http://bbs.keyhole.com/ - Developer discussion
• http://en.wikipedia.org/wiki/Google_Earth - Google Earth WiKi
• http://gearthblog.com/ (From Frank Taylor)
• http://googleearthuser.blogspot.com/  - Blog
• http://www.ogleearth.com/ - Blog
• Google Earth KMLs
• Article - Hackers Tap Into the Functionality and Simplicity of Google Maps

Do you have a GIS solution in the works designed to integrate GIS data with Google Earth? Please tell us about it.