Today, Paul Rademacher, a Technical Lead for Google Earth, announced the release of the Google Earth browser plug-in on the Google Lat Long Blog:

Today, I’m happy to announce the release of the new Google Earth Browser Plug-in, which brings the full power of Google Earth to the web, embeddable within your own web site. Driven by an extensive JavaScript API, you can control the camera; create lines, markers, and polygons; import 3D models from the web and overlay them anywhere on the planet.

According to Matt Goyer, it sounds like the functionality is something Redfin will integrate at some point.