Two Arduinos

No this is what they mean...

Transmitter: http://www.sparkfun.com/commerce/product_info.php?products_id=8946

Receiver: RF Link 2400bps Receiver - 434MHz - WRL-08949 - SparkFun Electronics

By the way Seeedstudio has them even cheaper - US$4.90 for the PAIR http://www.seeedstudio.com/depot/433mhz-rf-link-kit-p-127.html. Seeedstudio got them to me in Australia in under a week using the cheapest shipping.

They also have the Nordic transceiver you liked cheaper http://www.seeedstudio.com/depot/24g-rf-module-nrf24l01-p-214.html