I’ve just had way too much fun playing with KML Writer, a poor man’s Google Earth authoring tool. Just draw a polygon by clicking away in the Google Maps interface, add the amount of extrusion in meters, and export the result as a KML file that opens right away in Google Earth. You can even combine different polygons into one KML file. And it’s free.
One obvious use is making instant skyscrapers that really give free rein to your inner Trump. Here is my vision for Tompkins Square Park in the East Village, New York, circa 2016: Ogle Earth Towers (KML), a 300-meter high medium-income housing project to alleviate the housing shortage there. There’s always Central Park for those who need parks, though imagine the size of the things you could build in Central Park!
KML Writer is by Simple Spatial Solutions, a Canadian outfit.