I've been thinking about vision systems, and one idea popped into my mind. I know the intelligent weapons of the US army use this trick. Take a masked line CCD and spin it around a linear. By knowing the RPM and at least a single opto-trigger to track the RPM, an accurate polar image can be created. I've been thinking this could be interesting for vehicle guidance. Simply knowing the angle and the CCD that a "bright" target is lighting up, the position of an object could be detected. I might have to try this. Even with a single heat sensor, the ability of this design to easily zero in on a hot source could be interesting.
On a related note, how to do you control a spinning target? Especially if you don't have a stabe "zero reference"? One idea is to mount a microcontroller and a solid state gyro on a motorized plate. Spin the plate to correct for gross spin, and use the gyro for direction control and minor spin stabilization.