Ok here comes the party-pooper, Debbie Downer post...
Customized CM recognition cards are great. Really, they are. But the very best you're doing for that CM is giving them a 60 second smile and scrapbook fodder. Unfortunately, as in the post I quoted, showing them to a manager will not do a thing. The manager will say "That's nice" and everyone will go about their business.
If you sincerely do want to recognize a CM and give them some recognition that they can actually use, there are two ways to go about doing this. First of all, all the parks' Guest Relations locations carry compliment letters. Just go in there, tell the host you want one, and all you have to do is put who you're writing it to - "John @ Jungle Cruise" and then a brief message like "Thanks for making magic!". These *official* comment cards WILL go to that CM's manager and, not only is the CM recognized at the next local area meeting, but it also will go on that CM's permanent record which counts towards promotions, raises, etc.
Now number two is really to go the extra mile. Have a pen/paper with you and write down the names of the CM's that really do make some extra magic on your trip. Once home, take 5 minutes to write their names in a quick e-mail to Guest Communications. This works from the top down. Executives get this who then pass it to the managers who then pass it to the CM - thus EVERYONE knows that this CM did something good.
So, what I always say is by all means use the recognition cards, but do something for the CM that will really help them as much as they helped you. Let Disney know!!!