I haven't gone through each and every section & thread of MiceChat, so if this kind of thread is already existing, please excuse me and direct me in the right thread!
Anyway, while reading your celebrity sightings at Disneyland, it inspired me to memorize how many celebrities (movie stars, tv stars, singers, entertainers whatsoever) have worked in Disney parks before they became "bigger".
Despite of thinking very hard, I can remember only two people - although I KNOW there has to be many many more. Ex-mrs. Kevin Costner (I don't even remember her name, sorry) is one that I recall --- although I don't remember exactly was it in Disneyland and was she performing even Snow White..!!
Second person that comes into my mind is British actor Kevin Sacre (I liked his character very much in the short-lived, very bizarre television "soap" NIGHTANDAY). In his early days Sacre was performing Aladdin in Disneyland Paris.
So, if this kind of thread hasn't yet been invented, please continue sharing your knowledge - and favorites, personal memories, experiences, etc - on the subject.