[Image from Enha Wiki]
Sometimes, you have to ride bus, taxi, or something in Korea. And you don't have any money in your wallet. What will you do? In Korea, you don't need to worry about this. Because Korea has T-money!
T-money is a rechargeable card used for paying transportation fares. You can use it everywhere in Korea. Seoul, Jeju Island, Gyeong-Gi Do…. With this card, you can pay Subway bills, Taxi bills, Bus bills, and even can be used in Convenience stores!
T-money accessory version
[Image from Wikipedia]
Most of T-moneys look like Cards, like on first picture. But there are some special T-moneys like accessory version, or mobile version that works in your cell phone's USIM chips.
You can easily recharge your T-money card in Subway station, and Convenience store.
Bus's T-money reader
[Image from here]
T-money card is really cheap too! It only costs 1,500~2,500 Won($1.5~$2.5). And the best reason why Koreans use T-money card is that we can save more money than using a 'real money'. When we use T-money card in subway, it costs 450(Teenagers)~1000 Won($0.5~$1.00). But when we use real money, it costs 1150~1950 Won. Also, there is a transfer discount. When we use transportation after using another transportation, there is a discount. For example, when we get on a bus after using subway, we can use bus without a money. (If you tag your T-money on a bus, it'll show '0 Won used.')
When you are living in Korea, just go to convenience store and get a T-money. It is really cool!
P.S. English isn't my first language!