http://maps.google.com/
The maps thing has been rolled out to the UK, but they can't resolve the copyright issues for the satellite imagery, so we're not getting that
Alcatraz
http://maps.google.com/maps?&ll=...;t=k&hl=en
Excellent pic of the Grand Canyon Dam
http://maps.google.com/maps?ll=36.9....;t=k&hl=en