I doubt such an application exists, since Google maps are derived from a series of aerial images. In order for a real time view to be possible (even if it was just a specific country such as the U.S.), vehicles would need to be situated to cover every point viewable.
Perhaps you are thinking of some kind of webcam viewing extension within Google Earth?
I'd recently heard that Google Earth has some sort of software or an application, that seems to be an 'extention' of Google Earth, in which a person is able to view it in "real time"? I would imagine for a hefty price too. Is there such a thing available?