Picture event

Suppose you are to 'cover a topic'. You know that in about two weeks you and your group will read about shopping. Make your students go outside and take photos they can associate with 'shopping'. Create an event, invite all the members of the group. The date of the event is the deadline of uploading their photos on the event page.
The pictures can be used in class as visual stimuli for speaking. On facebook they will surely trigger comments.
You can as well tag pictures with names of things in them. (Any vocabulary can be presented this way.)