PowerPoint slide show

http://www.visual-idioms.com/

After your students have learned a few idioms, make a Powerpoint slide show of about 12 pictures (without the text). In class, show the pictures one by one (each for about 10 seconds). Then ask the students to write down all the idioms they remember from the slide show. When they finish, they work in pairs and compare their answers. They correct each other's mistakes and discuss the meaning of the idioms they've got. Later, show the slides again and check the students' answers as a class. This activity is good for revision.