Well folks, here's your opportunity to fulfill all your
childhood dreams of having a robotic helicopter. Check out the
Cheap Robotic Helicopter Howto. The intro reads:
This document explains how to build a 300 g, 3D-capable helicopter with
embedded Linux and Bluetooth datalink for less than 500 EUR.
The processor for the design is the Linux SBC
Gumstix.
Here are some links to various RC helicopters to get you started: