If you haven't checked out the freshly-launched Street View feature
to Google Maps, do so immediately -- it will freak you out. In some neighborhoods (major metro areas, so far), you can go from the grid view or satellite shot right down to a 360-degree photo taken at street level. What's more, you can then use Street View to navigate through city streets as if you were walking or driving around.
How the heck is Google doing this? Look in the reflection of the window in the picture above to find your answer. It's not magic, voodoo or wizardry; it's a dude in a crappy van