The New York Times recently visited South Korea to look at how people are integrating mobile phones into their lives:

Among all these features, however, one enterprise the country’s wireless carriers are banking on is bringing cash and credit to the mobile phone, “thus making South Korea a walletless, cashless society,” said Ju Hee-sang, a manager for mobile cash payments at SK.

Each month last year, four million South Koreans bought music, videos, ring tones, online game subscriptions and articles from newspaper archives and other online items and charged them to their mobile phone bills, without going through any bank or credit card.

Korean Insight wrote about a new royalty card program from SK Telecom using USIM  (Universal Subscriber Identity Module) cards:

Can you imagine that you collect your nectar point with your mobile phone? It might be possible in the near future because your nectar card function can be embedded in the USIM card in your mobile phone. This will definitely lighten you wallet, which are usually filled with a number of credit cards, royalty cards etc.