Google maps

I was astonished to see Google's satellite map tool, but there is more to it. It is not only use to find addresses but also to access services from other websites on top of Google maps. Housing maps uses craigslist to graphically locate and map all the house in the listing to their actual physical location. You can filter by price range and city. This tool is very helpful because you can see what place has a better deal,how far is the house you are looking from your work, university, metro station etc.
There is more to it. According to an article from the Washington Post there is a website, created by a 24 year old that uses google satellite map to pinpoint crimes in Chicago. (chicagocrime)
For the city of Chicago this web page has been a great help. People check crime zones every day to see how their neighborhood is doing.
Even though these sites are operating without Google's permission, they are doing nothing to shut them down. It is wonderful publicity for Google maps!