Nick Poole, from SparkFun, proposes this nice tutorial, where detailed instructions on how to connect a radio-controlled (RC) remote to an Arduino board are described in great detail.
RC remotes are very simple controller, typically used to wirelessly control electrical rovers, cars and planes. Depending on the number of degrees of freedom required by the application (e.g., X and Y movement), an equivalent number of channels is provided by the remote, that can be easily connected to Arduino’s digital pins.
More information and some sample sketches can be found here.
For more detail: RC remotes and Arduino: a tutorial