Well, must admit i do use google at times, (not to reverse search the pictures, but) for example to look up the cyrillic alphabet so I can find out it actually sais 'Tuva' on the seats of the sports stadium in that picture of Tuva's capital city. I play a lot of Geoguessr, a game that drops you in a random google streetview location and leaves you to guess where you are. It taught me to look for the tiniest clues, and it for example taught me you can recognize a japanes location by looking at lamppost (as they always seem to paint a yellow/black stripe patern at the bottom of those).
It's often not the total picture that gives me clues, but small elements in it, landmarks, bridges, surrounding terrain, color of the dirt, adverts in certain language/lettertype. You for example can sometimes tell that a city is northern or near mountains by looking at roof edges, because they have those 'snowcatchers' that keep snow from sliding down the roofs. Small clues like that can help immensly.
It also helps I do a lot of architectural research, mainly as inspiration for minecraft, and for the map editing I like to do in games. I have a general interest in architecture anyway, and have a shelf of books on it at home. I also used to download loads of landmarks for Simcity 4.
I've also been to all western european countries (except Ireland and Iceland), a handful of eastern european countries and a few north african ones. That helps too, especially when it come to recognizing the general architecture of a city picture. And I watch lots of discovery and national geographic channel XD
Anyway's, next to guessing, it would be cool if people would also post why they'd think it is their guess (like identifying landmarks, architecture and other clues). Whenever someone guesses a picture I'm always curious what lead them to their guess
