I have 3 computers with Google Earth.
What i want is to somehow make a KMZ file, that are being used by all 3 pc's via network.
So when i place a pen somewhere on pc 1, and save, the pen is shared to pc 2 and 3 aswell, live! withut the two other computers are needed to reopen the KMZ file all over again.
Is this somehow possible ?
Syncing multiple Google Earth desktop clients is possible if for example you update content on a server and have a NetworkLink (with auto-refresh enabled) load the shared KML in the clients but interactively sharing changes made in Google Earth clients with each other is not so easily done.
You can implement sharing using the Google Earth API and share Google Earth instances running in the web browser.
Here is the description of an example app in the Google Earth API Demo Gallery that may provide a starting place:
Earth Pad is an App Engine app that allows multiple users to collaboratively browse the globe. Earth Pad allows multiple users to share the same Earth viewing experience; when one user changes the view, it updates for the others. Users can create placemarks, which can then be seen by all the other users in the session, and even chat.
Note when you start the Earth Pad app it requests permission to access your Google Account and your email address to allow sharing a session. You'll want to run the app in multiple web browser windows and/or different web browsers. You can use one Google Account for that.
Visit https://developers.google.com/earth/documentation/demogallery and search for "Earth Pad" to jump to that application.
The code for the example is available here.
Update:
Note: The Google Earth API has been deprecated as of December 12th, 2014 so this functionality would need to be created using the Google Maps V3 API.