Write the names of the songs you want to review on separate pieces of paper.  Then take a potato and wrap it in one layer of foil. Then take the first song and place the piece of paper on the inside the next layer of foil.  The number of foil layers should equal the number of papers/songs you want to review.  You could add a few blank layers to throw them off.  Then during singing time, play hot potato. Have the children pass the potato while you sing the first song (your choice).  When the music stops, the child who was left holding the potato unwraps the first layer of foil. When they find the paper, they announce which song will be next.  Then sing that song while passed the potato.  You could sing one verse or all depending on time.