I've been a fan of Google Earth since the day it came out, and so when they added the capability to search the ocean floors AND Mars, I was thrilled. Now you can use Google Earth not only to fly around the world and visit places you've always wanted to see, you can also zip under the ocean's surface and check out the topography of the ocean floor, or fly to Mars and soar around the Red Planet. For more about this new addition, check out Google Earth: Now with Oceans and Mars.
Feel the need for a little travel? Try these resources: