Inspired by the thread on the Sacagawea dollar I pose the following question: Why not make money out of say, polyester fiber or even as plastic cards the size of credit cards with hologams on them to prevent counterfieting? Could it be done in a practical way?
Australia uses polymer bills. I asked about this once:
http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=124329
Euro banknotes look like paper, but they are made of cotton.
New Zealand has polymer notes too. They’re pretty cool, as they last longer (at lesat four times asa long as paper notes), are much harder to forge and look pretty damn cool IMHO.
Practicality?
Do you have, or have you seen someone with more than a few credit cards in their purse/wallet? Now mulitply that by several times when you convert thin currency to thicker plastic cards.
Are you sure credit card-type currency really is a better way to go? There are already counterfeit credit cards, even with holgrams. What’s one more step to counterfeit credit card currency?
What is the cost per thousand manufacturing paper currency vs credit card currency? It must be less.
Consumer acceptance. Americans refused the Sackie and the Suzie Dollars because they didn’t like them. The love afair with the almighty paper dollar runs deep. With the government spening in excess of $20-30 million marketing the new Peachy twenty-dollar bill – and being criticized for it – can you image the marketeering efforts for credit card-type currency? Can you say fleecing America big time?
Australian polymer currency might be a better approach.
Yet at the end of the day, when your country has the most prized / used / abused currency in the world, it may be the best route to stay the course just to be ahead of counterfeiters and please everyone else.
Am I the only one who sees the irony in the cost of manufacturing money? 
Brazil also uses plastic bills. Apparently they’re very good for when you forget about the money in your pocket when you go swimming at the beach. I’m guessing they’re the same as the Australian currency.
So are U.S. notes, technically. They’re made from “rag fiber.”
Why have cash at all? I’m still waiting for my implanted chip that carries all my info on it (like the magnetic strip on a credit card) and with biometric (I.E. - optical/DNA/fingerprint) id is virtually impossible to forge.
It would also change the light levels in my house as I move from room to room and open doors and deactivate alarms as I approach them.
I know it sounds out there but it’s not beyond current technologies. There was a professor at either Oxford or Cambridge a few years ago, with a chip embedded into him that was linked to the buildings enviromental controls and would open doors for him.
I think it would make more sense than cash but of course too much reliance on technology is risky (ever lost power for a few days? Makes you look at things differently).
Well, I have paranoia about the mark of the beast and all that, but I’ll admit I don’t like to carry cash and avoid places that won’t accept credit cards.
The Mexican MX$20 bill is plastic-ish, and there’s even a transparent part to it. It’s kind of neat.
Kevin Warwick.
He likes to present himself as some kind of cyber-visionary, but I think in truth he’s just a little bit bonkers.
Visionaries are really just loons that guess right.
My recollection of the Australian notes is that they are no thicker than US notes or not much thicker anyway. They are definitely nothing like playing cards. Plastic playing cards are stiff and brittle anyway.
I am sure the plastic could be done and they might last four times as long. Probably a good deal of inertia in US bills. Still cotton is a renewable resource and the plastic would not be.
It is specifically mentioned on the australian government’s webpage that the polymer bills (and the waste from their creation) can be and are recycled; they are certainly far more recyclable than standard “paper” money.
Also, it’s not necessarily a non-renewable resource. I remember reading multiple times years ago that some scientists had managed to create plastic from vegetable oil, or at least from genetically modified plants, I’m not sure which. I have not seen anything about this recently though so I do not know if I am mis-remembering things; or if said research got “suppressed,” as a conspiracy theorist would say; or if the process simply was not economically efficient (cheap) compared to the standard process of producing plastic out of petroleum.
Hm, can’t edit my own post to add something I forgot… anyway, I also remember hearing something about biodegradable plastic a few years ago. As in, it had actually been created. Again, what ever became of this?
Money would certainly become a lot more interesting if it was made of biodegradable renewable plastic, differently sized for each denomination so as not to discriminate against the blind, and equipped with more colors and designs and holograms and security features so as to both be less bland and be more difficult to counterfeit.
Of course, there may not be such a thing as paper money in 20 years anyway…
The real reason is that rich people can’t lightup a cigar with a plastic note. 
Quoth Kaptain Karnage:
That’s fine for transactions with merchants, but what about person-to-person deals? Say you’re at a friend’s house watching the football game, and you want to put a five buck bet on the outcome. Either you or your friend is going to need a biochip reader (which’ll probably be bulkier and more expensive than the chips themselves). Or a garage sale, or a kid’s allowance, or Tooth Fairy money.
IIRC the Euro was going to be made of plastic - but because it needed to be made in various countries, some of which couldn’t “do” plastic, rag paper was chosen
I’ve seen the Aussie bills. Very cool. They feel like paper and have a clear panel in them. They aren’t any thicker than paper. In fact, considering the strength of some plastics, maybe plastic currency could be thinner.