gistfile1.rb

class User < ActiveRecord::Base

  serialize :preferences
  
  def method_missing(method_name, *arguments)
    pref_match_setter = method_name.to_s.match(/^pref_(.+)\=$/)
    pref_match_getter = method_name.to_s.match(/^pref_(.+)$/)
    
    if pref_match_setter
      current_prefs = self.preferences && self.preferences.any? && self.preferences || {}
      current_prefs.merge!(pref_match_setter.to_a.last.to_s => arguments[0])
      self.write_attribute(:preferences, current_prefs)
    elsif pref_match_getter
      self.preferences[pref_match_getter.to_a.last.to_s]
    else
      super
    end
  end

end

# user = User.find(612)
# 
# >> user.pref_email_notification
# => nil
# >> user.pref_email_notification = 1
# => 1
# >> user.pref_email_notification
# => 1
# >> user.preferences
# => {"email_notification"=>1}
# >> user.save
# => true