During the 50th anniversary, Upper Deck produced a series of official trading cards. It turns out, there was also an exclusive set produced for Cast Members (although not quite the same quality as the mass-produced cards). I recently picked up 45 of these cards. I'm guessing this is an incomplete set. It would makes sense that there would be 50 cards in all. Also, it appears that they kept going after the 50th as I also have two cards from 2006 (in a slightly different format).
If you know anything about these cards including the total number of cards in the set, or have any information to share, or extra cards you'd like to get rid off, I'd love to hear from you.
Trading cards can be found here. The most recent addition are at the bottom.