It involves the learners thinking of something they like/hate doing; writing it down on a piece of A4 with a nice thick board pen; holding it up and getting a classmate to photograph it, as in the example, above.
It's most successful if you can persuade them to pull an appropriate face (demonstrate it to them) and, if you're taking the photos in class, maximise the English you get out of kids instructing each other how to pose the picture. Fabulous with teens and I've found adults liked it too.
Your learners probably have digital cameras at home (or if not, mobile phones in their pockets); if you have a blog or an Edmodo group they can then upload them directly to that, possibly from home.
If you are interested in good technology course, I can highly recommend the CertICT course.