Our friend Dave from Plastibots has just completed this great looking Bluetooth Robot that has an IP Camera on board. Dave wrote an Android application called BT Bot Control to allow you to drive your robot around using commands over Bluetooth using your Android phone. The video from the camera is sent back using Wifi. I can just imagine how much fun this would be with a squirt gun connected! Connect either a powerful solenoid or a servo to squirt the target when you have them in your sights. Might need some larger motors to get the speed you would need to quickly drive away before the person you squirted tosses the bot in the pool though.