When you have some more time, send me some info on how you pulled it off. I have been trying to come up with a similar stunt for my wife, it's our 10th anniversary when we go in early November.
From my angle, I was just waiting there and saw flash photography arround the corner and had no idea what the deal was. I though a manager was over there, though, so I didn't bother asking whoever it was to stop, I was just very confused.
Then I heard shreiking and "YES! YES!" saw a girl jumping around and screaming. It didn't take much to figure it out from there. We all thought it was really cool, it was the talk of the house for the rest of the night.