I don't think this will be a major concern until long after we are all pushing up the daisies. Even if they stopped using coinage tomorrow, the collective memory would take at least two generations to forget what a coin is....just my thoughts on this.

And even If they do Magicians use old Stuff People don't see any more all the time anyway! It makes for a nice story!

It's a very interesting conversation and it's fascinating to be active in magic at a time when things are evolving so much. As a kid I felt like there was kind of an established orthodoxy of branches of magic - with coins and cards being two of the deeply-entrenched branches. But in recent years we've seen so many new areas emerge - magic with cell phones, iPods, credit cards, packs of gum....with strange little baby arms that pop out of your hand....ok maybe that last one isn't going to become it's own branch...I suppose it's possible that this kind of evolution has always been a part of magic and I just wasn't aware of it when I was reading through The Amateur Magician's Handbook in relative isolation as a kid...but nonetheless, because of societal shifts we've seen certain types of magic already fade away. For example, hardly anyone does cigarette magic anymore. I am sure it will take a long time before coins and cards are affected in the same way, but I think it's inevitable that over the long haul a shift will occur. It's interesting to think about the possibilities for magic with the smaller digital devices though, including the ones yet to come...where sleights and electronics could be combined.

Egad! Thanks John! Now, I'm heading to town to buy a new (bigger) hat!

NOW, Here's an old, but somewhat humorous story, that may calm down those who may be concerned with an impending "cashless" society:

It was a college class, the professor was lecturing about astronomy. His closing line was calculated to shock the listeners. He said, "We now can project that, in about one billion years, our sun will have used up all of its hydrogen and it will burn out!" A student leaped to his feet, waving his hand excitedly. The professor recognized the young man. "Yes. You hava question?" The student responded, "How many years did you say?" "I said ONE BILLION years." "Oh, thank heaven! I thought you said ONE MILLION!'

They will gain value as conversation pieces, much as people under the age of 30 already prefer distressed playing cards.

Playing cards, incidentally, will suffer the same fate as coins -- online poker, Windows solitaire, etc. So card magic has a similar issue of presentation.