My first Robot- basic drive system

This is my first project so far. I have got the basic forward system almost working, and was wondering if anybody had any tips/improvements? It runs straight and I have made the treads tighter to get more force from the wheels, and it turns fine..  got some pics, just done quickly from my phone.

I think that with everything from only 3 AA batteries, the motors are not getting the power they should. I may connect some kind of rechargable power pack as well. the treads are coated in correction fluid to reduce friction a bit. I also found that an LED can be run from the output pins using the motor driver, allowing lights that are on/off depending on the direction of the robot.

The next step

I will probably add a SRF(04, 05 or 08)  with a servo, and may add a laser diode for some cool effects.