Flyff

Flyff (or Fly For Fun) is a free, Korean-made MMOG; it is similar to other games in the genre in that you control a character within a player populated world, and it is set in a fantasy type setting where swords, magic, and monsters are commonplace. What sets Flyff apart is the fact that you can fly and that it is a well-integrated aspect that you can gain fairly early in the game.