Hope I'm not putting this in the wrong thread, but I haven't seen mention of it elsewhere on arkgeo... move it if you want to.
Premium members at geocaching.com can go to My Account and on the right side under Google Mapping Features select Download Geocache Browser in Google Earth.
This installs a really cool satellite imagery program with geocaches overlaid.
It's only accurate to ~100', so it's really no good for geocaching, but for finding caches you want to go to and finding access roads, etc. it's great!
The resolution varies across the country, but in my area it's pretty good - I can see my dog in my back yard! In most areas I have looked at you can pick out objects such as a telephone pole or a particular tree, in some high-resolution areas you can get better than that.