Here is a map of a recent cross country ski run I made.  I had a GPS with me while skiing and then converted the track points to a KML file.  The file was uploaded to Google's My Maps section where it can be referenced from other sites.

 

Why Google Maps instead of, say Microsoft's Virtual Earth?  Well, in the world of online maps things are still a trade off... when it comes to maps of the Juneau / Douglas area, neither are perfect.  Google's map base provides greater coverage of the higher resolution images for areas that are not directly on the roadway.  The following link will show how Virtual Earth is missing content, a good section of my ski path is off the map.

 

 

On the other hand, Google's street map provider (Tele Atlas) has horrible data for the Juneau area.  Many of the streets are off by a couple hundred meters, some even run right through the channel.

 

So, if you are in Juneau and want your streets to line up with the imagery and don't need images well off the beaten path, go with Virtual Earth.  If your going backcountry, go with Google Earth (Google also seems to have fewer clouds in their images).