Check out WireLess Gate Shield – make a system of receiving / transmitting and broadcasting various wireless commands and data on your Arduino. Features interface to connect the transceiver to 2.4 GHz nRF24L01+ and to connect the transceiver to 443 MHz RFM69HW (HopeRF). Includes a real time clock module DS1307 on board, user LED, IR receiver and Grove-compatible connector.
Buy WireLess Gate Shield from Pakronics:
WireLess Gate Shield