Since a couple of weeks back Emma and I have been using PASMO. Here is the definition according to a subway station guide.
PASMO card is a convenient prepaid transportation card that contains an integrated-circuit (IC) chip, allowing the user to enter the subway by simply swiping the card over a PASMO reader located on the ticket gates. The card is rechargeable and can be used over and over. It also can be used interchangeably with the East Japan Railsway Co.'s (JR) Suica card. In addition to using your charged PASMO card to ride the subway or bus system, you can use it to pay for items purchased at stores and vending machines. The PASMO card can also be used for purchases wherever you see the Suica logo.
So this is why I really love PASMO! You just beep the card at the ticket gates in the subway when you enter and when you leave and it deducts the correct amount from your card.
You buy the card from a vending machine and there are basically two versions of the card, one that is connected to you personally and one that is not - so everyone can use it freely. If you choose to personal card you have to provide a passport when buying it, the advantage of this being that if you loose your card you can reclaim it with the amount that was left on it.
So here we've got a card that you can use to pay for stuff really fast, it literally takes milliseconds for the purchase to go through, and a lot of convenience stores like AMPM takes PASMO, so it can actually be used as a replacement for cash.
I like credit cards and I don't like carrying around lots of cash in my pocket. But there is a very large downside to credit cards, if someone gets a hold of your card they have full access to your entire bank account until you have time to block it, which if you don't notice that it's gone or if your robbed and they steal your phone too, can be a pretty long time.
With PASMO you only keep it charged with a reasonably small amount at any given time, the maximum amount allowed to store on it is (I think) 30 000 yen. So if it's stolen or you loose it, you can't loose very much, just like cash. If you have the personal card you still have the option to block it as well. So you've now eliminated one downside to using a credit card.
The second big downside to using credit cards is time, you have to take out your card, swipe it (and hope the magnetic strip isn't wiped, something that happens quite often) and then wait for confirmation. Every store has to be online to check that the card is valid and all that. All of this takes huge amounts of time, and banks usually charge the store a small amount for each card-purchase they handle (at least in Sweden).
With PASMO, you simply keep the card in your wallet and put it up against an IC-reader and radio frequencies does the rest. Everything is over and handled in milliseconds, because the IC on the card keeps track of how much money is on there (I assume). I don't know how hard it is to hack, but I assume here as well that it's pretty damn hard because if people were doing it, they probably wouldn't have the card. The reason I don't think they store the charged amount in a central database is that it would require every vending machine in every street to be online and that seems unlikely.
So, PASMO is the perfect blend of the safety of cash with even greater ease of use than a credit card. It's simply fucking awesome.
