[CoolCzech]

Doesn't really matter - Pusan is the English version, Busan is closer to what Koreans would say: they don't use the Latin alphabet though, so I guess those that DO use it should have right of say. When my Korean wife says it, it sure does sound like a "p" sound to me, but she insists it's really closer to a "b."

Either way, both ways of writing it are closer than Prague vs. Praha, for example...