Google Earth is an interesting website that can help you with your prepping. It provides satellite views of just about anywhere on earth. It is kind of like having your own satellite, but unfortunately, it is not in real time like the governments. However, it still can be of great benefit to you. You can go to http://www.google.com/earth/download/ge/agree.html and download the latest version.
First take a look at your own home or bug out location, this gives you an idea what your location looks like from a satellite. Be aware that other people may be looking at you on Google Earth. Use Google to take a look around your neighborhood. A friend did and found a swimming pool a few houses away of which he was unaware. In an emergency, you know that they have water, but they may not have the means to purify it. Your purification equipment and their pool can be a win, win situation.
You can use Google earth to find every pond or swimming pool within walking distance of your house. Looking at your neighborhood gives you a whole new perspective, you will notice things of which you are unaware.
Check your bug out routes on Google Earth, particularly choke points, you may find routes around them. You may find hazards that you have not known about.
The government spends millions of dollars every year on satellites to gather information. Of cause we can’t match that, but I found out that some of the trails in my neighborhood are very hard to see from above because of the trees. Look at Google as an intelligence tool. You can vary the light so that you can see your location in all different lights. There is also an historic record so that you can see past photos of the same site. This helps you to spot changes. Both of these apps are located on the tool bar at the top.
Of cause in any real emergency, Google Earth will be down, but use it while it is still available to plan your routes or other strategies.