This is an effect that I've been meaning to try out for some time. I originally saw the effect on a blip - I'd seen someone's blip where they'd used a polarising filter on their camera, and held up a cd case in front of a computer monitor. The effect was really interesting - it showed all the strains in the cd case in a kind of oily rainbow effect - I'd bookmarked the blip so I could credit it when I tried this out, but I lost it in the great Firefox crash of a few months ago.

So, what I did here was take a vase I have (with lovely swirly cuts in it) and placed it in front of my monitor. I used a white background on the monitor (MS paint comes in useful!) and tweaked the polarising filter so the monitor looked black on my camera screen. I then tried out a few compositional shots to get the idea of what I wanted to do. I took a cd case and put it between the camera and the vase - suddenly all these pretty colours were showing!

This is the photo almost as is - tweaked a little on saturation/contrast/smoothed out noise/cooled down the colours a little and healed up a few bits of dust that had sneaked their way onto the vase - I didn't add any extra colour to this!