Google has just announced a new Google Earth API – which allows embedding and fully functional Google Earth in just about any webpage. Even is easily intergratable with Google Maps API mashups – with very little extra code. (takes a number of seconds for that news to sink in!)
…Windows only btw…
Expect A LOT MORE from this very flexible looking API – the JS interface can quickly interact with objects (API is based around KML) and gets pretty good control of interface options.
Update: mentioned on gearthblog.com which is a good introduction about what this is and what its not!
Update2: and to show it can basically be added to a ‘real world’ Gmaps mashup, in a few lines of code, see here