Is This Useful? - Google Street View
A while back I posted about interesting maps (actually in 2005!) and listed out all the interesting map sites. At the time, Amazon's maps.a9.com was the most innovative because they had street level imagery. They've since shut down, but today Google Maps took it to the next level with Google StreetView.
Not sure why you'd want to watch a blurry video rather than just going there, but you can see a demo on YouTube if you like.
The embedded Flash has a nice draggable cylinder view like QuickTime VR, letting you see any angle stitched together.
The user interface is pure brilliance. Pick up the little yellow man and drag him, and his little feet float in the wind as you drag him round, until he's firmly planted on virtual ground again. A green arrow indicates which direction he's facing. Even arrow keyboard hotkeys work as they should!
Here's the real question - is this useful?