Near to Here
Near to Here is an iPhone application that uses Google Maps to show you the interesting things around you.
The Near to Here application determines your current location and finds nearby interesting stuff. As you pass by landmarks the application alerts you with the Wikipedia entry of those landmarks.
The developers of Near to Here say that "whether you are passing by a plaza in Rome, playing near a fountain in Paris, strolling through Times Square in New York ... this application will give you all the information you need to be an informed traveler."