Now talking serious,
Nery Castillo rejected the offer that the Coach of the Mexican National Team (Ricardo Lavolpe) made. The president of the FEMEXFUT and the Assistant Coaches of the Mexican N T even went to Greece to try to talk him to play for Mexico. Uruguay doesn't even care about him, they know about him, but they don't need him.
I think that his best bet right now could be becoming a Greek Citizen and play for Greece; considering that he burned his chances with Mexico and Uruguay.