How does one get the blank slot cards that I've seen mentioned? I have my own cards, and each time I go back to Las Vegas, I get new ones (left them home, etc.) and many times, the cards have changed in a minor way. As to their worth? Who cares. In additon to being a definite part of casino history, they're fun to collect and my binder pages are colorful. I also have a few cards that I found with names on them. I saw mention here that the magnetic strip on the back of the card contains information and wonder if they should still be traded or can the strip be demagnetized? Thanks.