I have always disliked the use of crib sheets in singarounds. I feel that if you cant learn a song then it shouldn't be used.
I saw the ultimate a couple of weeks ago in an informal session when one person got out a laptop and set it up on a music stand and proceeded to go through lists of songs to find (Quote) "One that I might be able to do" I find that those who use crib sheets usually get it wrong anyway.