Note: this is a really _really_ minor thing that just annoyed the hell out of me, so I’m writing down how to fix it.
Google Maps and Earth use an XML-like format called ‘KML‘ for storing placemarks and map info (or ‘KMZ’, which is just zipped kml — useful for larger amounts of info, like map overlays and the likes.
Unfortunately, it appears that Google Earth is a lot more tolerant of slight errors in KML files than the Google Maps API, which is used by applications like the excellent WordPress Geo Mashup plugin I use on this site.
I have a basic collection of placemarks to show where I’ve traveled and lived, it’s sort of a map diary of mine. Google Earth is a convenient way of dealing with it, since unlike Google Maps, it allows you to put placemarks in folders/subfolders. The downside is that you can’t have access to this information online, which is not an issue for me since I usually carry a laptop around anyway.
I use yellow and red pushpins,
which worked fine in Google Earth, but found that when I exported my placemarks KML file to Google Maps (either on maps.google.com or here), most-but-not-all were replaced by blue markers.
I finally figured out that Google Earth tends to sort of randomly assign placemark styles (defined via the <styleUrl> tag early in the KML file) to places — so even if you’ve manually set all your placemarks to use the same yellow pushpin, you may find your placemarks using 300 different placemark styles. For some reason, a lot of them were horribly munged, referring to URLs rather than styles defined earlier in the file. Google Maps got confused. I have no idea why this happened, but it’s obnoxious.
To fix it, I also realized that you can recursively set placemark styles for all placemarks at once — create a placemark folder in Google Earth, put all your placemarks and placemark subfolders in it, then set the placemark style for the folder and everything in it to the placemark you want.
Then, go through your placemarks and individually fix the ones you want to be different.
Even though the KML file will still have many styles for placemarks, you’ll notice that Google Earth speeds up a bit, and Google Maps now understands all your icons.
