XBee Direct Wireless I/O Passing
A Digi International Series 1 XBee 2.4GHz radio module has the ability to directly pass through digital and analog I/O lines. Simple (transparent packet-based digital) radio links for controlling actuators and sensors can be made with no external microcontrollers in the loop.
In this video, the transmission of 1 analog (via PWM) and 1 digital pin between two XBees.
Details on how to configure your radios in http://www.etotheipiplusone.net/?p=748