Here is a fun game to play with friends:
You will need a place where people are at. I like tourists. Anywhere with a crowd (but it is nice if that crowd might have some cameras). You will need, also, several friends. You and your friends will go to the place with your own cameras (also you need cameras) and you will take pictures of each other taking pictures. The goal is to get as many pictures of the other players taking pictures as possible without being noticed by the people you are photographing. The secondary goal is to notice anyone who is taking a picture of you and make sure they do not get a shot of you taking a shot.
Go. Play.
