hmmm, these are the names I came up with:

Josh Hartnett = Tidus
Scarlet Johansson = Yuna
Daryl Hannah or Demi Moore = Lulu
Lindsay Lohan = Rikku
Benicio Del Toro = Wakka?
Arnold Schwarzenegger = kimahri
Christian Bale = Auron
Joaquin Phoenix = Seymour
Hugh Jackman = Jecht

now when Jecht turns into sin, I think they should design him like that giant bubble alien at the end of that Evolution movie...

They should make 2 versions of this movie.. a serious one and a parody (which ofcourse has to have a completely different cast)