A blog called b3ta challenges tries to imagine how our world would look like if Google ruled it. Google would know your favourite songs, your past habbits, your friends so you could use it to find your keys, songs you used to listen or information about your bank account.
You could translate any book in your language, report information about fugitives using Google Maps, find Osama bin Laden, play with genetic engineering using Google DNA, find arguments pro or against any opinion.
Your shopping cart would have information about the products from Froogle. Outdoor banners would have non-obtrusive AdSense ads and every street sign will include maps from Google Maps.