override message for validations

Hi all,

Is it possible to override the default rails messages (:message => ) for validations (validates_presence_of :first_name, :last_name, :email, :message => "you moron!") application wide without changing the rails code itself.

I need to translate it but want to avoid putting the translation next to each validates_*

I prefer not to do to change rails code since I feel it hardens upgrading.

Regards, Stijn