Just saw the news about the newest version of Google Earth (version 4) being released in Beta. You can download the beta and have a play from the Google Blog.

"Google Earth now covers more than 20 percent of the landmass of the entire globe with high-resolution satellite imagery (soon Google Maps will too). When we say "high resolution," we mean the good stuff: you can see cars, houses, buildings in more than 200 countries and territories. Not every house is covered, only about two billion of them. That's our best estimate, anyway — that about 1/3 of the population of the Earth can now see their homes in high-resolution."

There is also a bit of commentary from a user's perspective on this blog.