# File app/models/sys_conf.rb, line 16
  def self.value_for(key)
    k = key.to_sym
    now = Time.now

    return @@cache[k][1] if @@cache[k] and @@cache[k].is_a?(Array) and
      @@cache[k][0] > now - 2.seconds

    item = self.find_by_key(key.to_s) or return nil
    @@cache[k] = [now, item.value]
    @@cache[k][1]
  end