An export of my (brand new :) WBT-200 gps logger:

http://maps.google.com/maps?f=q&hl=en&q=http://www.seweso.com/blog/Track.kmz&ie=UTF8&z=11&om=1

very cooliedewoopsie

Here's the one I did for my site Another Chance To See a while ago...
http://maps.google.com/maps?f=q&hl=en&q=http://mywebpages.comcast.net/anotherchancetosee/ACTSmap.kml&ie=UTF8&ll=-7.013668,43.59375&spn=178.730328,360&t=k&om=1

Original blog post at
http://anotherchancetosee.blogspot.com/2006/07/google-earth-another-chance-to-see.html

Mine says "<Placemark> contains syntax errors" about 50 times! (have about 200 placemarks on the map)
But this works in Google Earth except some of them it never plots since I do not have the Geocodes

Does anyone know if this you can add a KML file to a map using the API?