More robots on the way

Having recently brought a couple of robotics books and subscribed to Elector, I have whetted by appetite at doing a vehicle based robotics project (having designed UAV's and submarines). I guess after the vehicle there still is boats, hovercraft and choppers, but while I'm on to vehicles, I have two different designs I want to create.
1) A basic line following robot (using a couple of IR LED/reciever pairs will follow a black line of electrical tape of a white surface). This will be more of a proof on concept - small scale project, just to get into the swing of control systems again. I envisage using a PID control algorithm to keep things on track.
2) A larger more robust robot fitted with a xy adjustable video camera - transmitting to a remote location. Hopefully I will be able to experiment with inertial navigation (augmented with the GPS module from our UAV) and will have a bit more expertise in mechanical construction designing driver mechanisms. I'd be nice to also have an adjustable height camera (can extend up to look over barriers) and possibly some sort of audio link (so I can communicate with people the robot sees). I'll also be a good excuse to get the welder out and build something cool.