There are several solutions for storing translations, but most of them involve additional migrations for each  translated column. A more as-you-go solution offers translated_attributes Rails Plugin

• stores all translations into one ‘translations’ table
• AR-like interface (validations/update_attributes etc works)
• performance (only one request to translations table for any amount of translated columns)

class User < ActiveRecord::Base
  translated_attributes :name, :about, :description
end

User.new.name = 'Myself' #stores name_in_#{I18n.locale}
User.new.name_in_de = "Ich"
...

Have a look and tell me your opinion!