Hash#symbolize_keys/symboilze_keys!

gistfile1.rb

class Hash
  def symbolize_keys
    inject(Hash.new) do |result, (k, v)|
      key = k.is_a?(String) ? k.to_sym : k
      val = v.is_a?(Hash) ? v.symbolize_keys : v
      result[key] = val
      result
    end
  end

  def symbolize_keys!
    replace(symbolize_keys)
  end
end