I read about the following website from the Google blog. You can explore all of the US presidents on the Google Earth map. View their birthplace and click on the number icon to learn more. You can also see a progression of the states that voted during each president's election (shaded in red).
I heard about these other Google features a while ago, but it wasn't until recently that I was able to take a look at them. Google Body allows you to explore the human body just like you would in Google Earth! It is amazing! The other link is for the Google Art Project. Here you can discover and take tours of famous art museums from around the world. You can also zoom in one any piece of art to get a closer look.
Google continues to expand their repertoire! They amaze me with the amount of content they provide for free.