I had read about getting the birthday button before dh and I went to Disneyworld for the first time, so we made sure to go to MK on his bday.
We had 3 fun things happen...first, we saw Ballou, and dh wanted a photo with him. While I was taking it, Ballou saw the button, pointed it out to the cast member with him, and she had everyone around sing happy bday to dh.
Second, we ate lunch that day at one of the cafeterias. We ordered our lunch and paid for it. When we got to the counter to pick it up, the gal putting our food on the tray saw his button, and added a box of animal crackers to the tray.
Third, we were at the Sword in the Stone ceremony, and Merlin picked dh. As it turned out, Merlin accidentally had his wand set on "bodyguard" so dh was not able to get the sword out, but he was the "bodyguard" for the little girl who was able to pull the sword out.
Needless to say, we're going to be at MK again on dh's bday, and we're getting him the button.