Spaw, Andrew Lloyd Weber doesn't usually write the lyrics. It's often Tim Rice, but it has been other lyricists, too.
Jim D., I like those stories about the non-mondegreen types of screw ups. One that I've done once or twice before, when my mouth was on auto-pilot, was to inadvertently change the last line of "Hey, Good Lookin'!" from "How's about cookin' somethin' up with me?" to "How's about keepin' somethin' up for me."
BTW, Jim, "When it came time to perform it in concert, half of them--the ones who had been in the car with me--started off in 4/4 while the rest started off in 3/4!" -- Isn't that called "jazz?"
There's another mondegreen website called "amiright.com".