How to use Google Earth to accurately display geocaches
Google Earth (www) is a powerful program that models the earth in 3D with arial or satellite photo overlays. It also can display things like roads, businesses, and driving directions. Additionally, if you download the "Google Earth KML" from your geocaching.com profile page (it's on the right-hand side column), you can view the approximate location of up to 150 geocaches at a time in your Google earth screen.
KML file inaccuracy
At first, you might think that this KML download is all you need to find geocaches without a GPS. However, you quickly notice that when you zoom in, the caches seem to jump about. This inaccuracy was designed into the KML file. Every time the camera in Google Earth moves, the KML refreshes, and the geocaching.com server sends a new location. The locations where you see the geocaching icons are never the actual locations!