drJackel
They drive around in cars with roof mounted cameras, continuously taking pictures.

Jason
They have a car with cameras mounted on top that produce images that when spliced together form 360 degree views of the street or highway they are driving on. They have been doing this for a couple years now. I believe the project is incomplete at this time. I agree it's very interesting, you can visit many cities and towns in many parts of the country and some outlying areas too. It's also helpful when planning a trip even just across town, to know where to turn and exit, to see and recognize physical landmarks, etc.