Loved Kevkrom's list! But actually, the "I have a cold" excuse is the only one I have sympathy for. Back when I was doing a lot of singing, I used to have a devil of a time with my allergies. And a bad cold or bad allergies mess up your instrument something awful -- it's like taking a trumpet and pouring a jar of peanut butter into it. Glub, glub! If you have a stuffed-up head cold, the sound simply won't resonate properly in your nasal passages (goodbye head voice and high notes!) and if your throat is messed up, your voice will crack on your "break" notes (the ones in between head and chest voice). And just forget it completely if you have bronchitis.
Of course, all that said, for most people, "I have a cold" really means "I'm scared to death and haven't been practicing like I should!" LOL!
All that's true, but it's also generally said by the ones who can't sing worth a lick anyway. :) I remember last season when Mandissa had a cold and had one of her weaker performances but she was still did a good job. I liked Kevkrom's list too. Hopefully we'll see someone next week and we will all go, that's it, there's the one to win. :)