I've been playing around with some of the electronics for my tank model. One area I thought could be interesting is using Programmable IC's for controlling some of the lesser functions of the vehicle.
The vehicle I'm modelling is actually a Games Workshop Tank which has side mounted sponsons on each side with a small turret.
I thought it would be nice to be able to control these with a switch, which would initiate some kind of sequence of turret movements, gun elevations and flashing lights, possibly sampled sounds too.
I've got the turret to work from a switch operated from the transmitter which provides a digital input to control the weapons movements. The pic chip I'm using is a PICAXE chip and a servo control board from
http://www.rev-ed.co.uk/picaxe/
The boards are pretty cheap too and provide the ability to program the movements of up to three servo motors or a mix of inputs and outputs / lights relays etc.
The picaxe chips don't require a special programmer and can accept basic code straight from a PC. They would be excellent for controlling servos for aircraft undercarriage and gun turrets on r/c boats etc.
Fun stuff!