Via WorldCAD (Link) comes word that Google is apparently integrating some of the previously professional-level drawing tools into their free version of the Google Earth application. From the GE 4 beta page (Link):

We have improved icon management by creating a new icon palette, added line and polygon drawing tools to our free product, added the ability to print search results and placemarks, made it easier to select icons that are overlapping, and much more.
…
Drawing Tools: The path and polygon drawing tools are now available in the free product. You can easily sketch figures on the imagery for richer annotations and can share these overlays as KML or KMZ files. These features can be accessed from the toolbar.

One wonders at what point there’ll even be a paid version.