Royale has updated his PSP Maps app to version 1.1. If your not aware of this program, its much like having google maps, Yahoo maps and virtual earth all in one package. This version adds an experimental and basic KML files support.

KML support:

• Create a kml/ directory in your PSP-Maps folder.
• Copy the .kml files in this directory.
• Currently, it only supports “Points” and “Lines”.
• If you create an .png image with the same name as your KML file, it will be used to replace the default marker.
• You can easily create directions with this link (replace the towns in the URL): http://maps.google.com/maps?output=kml&
  saddr=toulouse&daddr=paris

Source: Royale.zerezo.com