Chris Hadfield wrings out a washcloth in space, proving once again that every single thing you do is 100x cooler in space.
Lava Carbuncle - an ancient intrusion of tough, hard rock in southwestern Africa. Quite likely also Namibia.
Another one of my favourite space images - the ISS high above the Earth, as seen from a Soyuz on the final Space Shuttle Mission. [Edit, I don;t know how I got the two craft mixed up. Must be one of those days.]
The Grand Canyon from Space [HD]
Whaddup scar of AZ