We took our daughters (ages 5 and 8) on their first geocaching adventure this weekend and it was great! We used the very popular Geocaching.com website, which had quite a few Google Earth tools to make our adventure easier to plan.
In particular, they have a Geocache Google Earth Viewer that you can download and use. It's essentially a network link that shows all of their geocache locations in Google Earth -- over 1.6 million of them!
It was quite handy to fly around in Google Earth, find local caches, then click to see if they were worth checking out. We eventually stumbled upon a local "challenge" (10 locations to find, including this one) and had a good time.
While the icons are clickable, I would like to see them have a bit more info. In particular, the "last found" date would be helpful, so you could quickly see if a cache was likely to still be in place.
They also integrate Google Earth by allowing you to create "routes" that are generated by uploading KML files.
For all of you geocachers out there, what is your favorite way to search for new caches to find?