Although I have not tried it, this site claims to preview your KML on Google Maps, which is certainly easier than tweaking you code, uploading your KML to a server and reloading it with each change you make.
Tuesday, June 24, 2008
KML Samples in Maps
Curious how KML elements appear in Google Maps? Take a look at this sample file. Check any item to display it or click a link to zoom in. Google Maps supports a subset of KML features, as described in the KML documentation. Of course, you can view a KML sample in Earth as well.
Posted by John at 11:36 AM