Flags are excellent for decorating the classroom. But beside that, flags are terrific tools for helping students learn the names of counties as well as nationalities in more realistic way.  Moreover, flags can be easily used into  guessing games while practicing the correct structure of making and answering questions. You can choose a students to guess what is his nationality by hanging a flag on his back. The chosen students will have to discover the country while making and answering questions until the country is guessed. This kind of activity has proven quite beneficial as it transforms the tedious grammar drills into interesting and engaging guessing games.  It can get even more engaging if all students play this guessing game. That is they ask each other questions until they finally discover their nationality represented by the flag . The flags can be used for singing songs together with waving the flags of the named country. There is a wide range of possibilities to integrate flags once they are created or printed. 

What kind of activities would you suggest  to integrate flags into ELT classes?