I think students of any age love correcting their teacher.  With older students you could use Wyn Parry’s speeling misstakes and with young learners you can use these great two-minute flashcard activities from my colleagues.

Put the flashcards on your head so the students can see them and then pick one and say a word.  Students say “YES” if you’re correct and “NO” when you’re wrong – then you can ask them what it is and they say the correct word.  ~from Beth and Elen

Do songs without the CD so that you can sing them more slowly and hold up the wrong flashcard.  If you act like you’re convinced that you’re right, students will love it even more! ~from Simon