Thessaloniki,Greece, Galerius' Triumph Arch, 2011
Flickr is almost certainly the best online photo management and sharing application in the world. Show off your favorite photos and videos to the world, securely and privately show content to your friends and family, or blog the photos and videos you take with a cameraphone.
The Acropolis, seen from above. I remember several professors diagramming the layout of the temples as an undergrad, realizing that there was far greater and more complex order in the layout of all the pieces than I could have imagined.