Street View
If Apple can replicate street view, I'd be impressed.
Will we see a fleet of Apple branded camera wagons careering around the streets of the world?
Street View is Googles killer maps application - it really is that remarkable.
I've used it hundreds of times and when I drive to the location I've viewed online, it really does feel as if "I've been here before"
It also is massively useful when scanning for property - I'm currently looking to move to new rented accommodation and street view provides a way to have a look at the outside of a property and the surrounding area. Estate Agents are often less than honest :)
Then we have Google Earth - admittedly, it's not something I use that often, but from time to time I find it useful to brush up on my geographical knowledge.
Then the standard map view - it's impressive.
The only thing it's missing is ordinance survey - which is the only time I head over to Bing maps.
There's obviously a whole other side of digital mapping the public is generally unaware of, there are plenty of niche companies providing a level of data which is quite simply astounding. For instance, mapping which shows all the underground pipework, shows flood risk, detailed vector views of properties - you name it.
I often wonder whether those companies tie in with Google or Visa Versa, providing services? I suspect they must do.