The idea is simple really. Like a word chain game;
Person A would have to find and take a picture of, for example a television:
So television ends with the letter N. Person B will need to try and find something beginning with N.
|Ha ha, the word beginning with N is Nutella (Not the squirrel)|
So now person A will need to find something beginning with A.
|Of course, It's an Apple.|
and so on and so on.
To make things harder could have themes, like only objects that are red, only things that you find in your house, electronic things only, only food, etc etc.
Or maybe its already out and I just haven't been able to find it yet. :-P