One of the teachers comes up front and has the children say the memory verse on the PowerPoint with them .   "HeyMan" (Haman, from the book of Esther) then comes up, and tries to convince the children to not listen to the teacher, but to listen to him and not say the memory verse. 

He then shoots the PowerPoint screen, and one of the words "magically" disappears.  He leaves thinking he has ruined it for the children.  (You can use any kind of gun, a toy laser for a futuristic look, or a toy six shooter for an old western theme.  When HeyMan shoots at the screen, simply cause one of the words to disappear on your PowerPoint presentation.)  The teacher then has the children say the memory verse with one of the words now gone.  HeyMan comes back up angry, and again tries to get the kids to listen to him, and not say the memory verse.  He asks the kids if they really believe in what the Bible says, and the children without any coercion from the teacher will answer yes.  When he fails, he again shoots one of the words and leaves thinking that they surely won't be able to say the memory verse now. This goes on for as many words as you have. When the last word is shot, HeyMan leaves for good, but the children have memorized the memory verse. 

For added fun, have HeyMan shoot the words in different silly ways.  For example, he can shoot the word from behind his back.  You can also have a lot of fun with HeyMan's name.  For example, when HeyMan is talking to the teacher, he can say, "Hey man, ..." and the teacher answers, "I'm not HeyMan, you are."  HeyMan then says, "I didn't say HeyMan, I say hey ... man." 

For more fun, HeyMan can have friends (his gang).  In our church, he has a friend that tries to come up and help, but when he shoots, he misses the words.  Sometimes we tie a string to HeyMan's hat, and his sidekick shots it off instead of the word.  Be creative and have fun.  The sky is the limit.