Building a Thermal Camera
Being a programmer, but not an engineer, I always wanted to try to create a camera with the ability to micro-shift the sensor in both directions, increasing the resolution. If you shift 3 times by 1/3 of the pixel on each axis, you can theoretically 9X the resolution (well, megapixels). Of course, it won't work for dynamic scenes, but could be quite useful for industrial scanning or looking for house insulation problems.