ANSWER
It was first said December 15th, 1956 in Shreveport, Louisiana by Horace Logan, producer and host of the Louisiana Hayride radio show. It was Elvis' final appearance on that show, after performing for Logan for two years. Unlike the meaning of the phrase in later years, Logan was actually trying to entice the fans back to their seats, as there were still other acts yet to perform that night.
WHO GOT IT RIGHT: Ryan Scannell, JP Weigt, Bob Milligan, Marika Thiessen, Matthew Toups, Scott Nilius, Marc Quinlivan, Christine Severen, Andie J, and Robin Campbell.
