I've recently fallen in love with a book I checked out from the library called: The Photographer's Guide to Filters by Lee Frost. Truly an eye opening experience. Dozens of ideas were sparked from this book. I can't wait to see them come to fruition.
One of the techniques mentioned in the book is called Cross Polarization. Here's a quick how-to: You'll need 2 polarizing filters. One on your lens and one over a light source. Put any piece of clear plastic in between the two, rotate your polarizer, and you'll begin to see the stress marks in the plastic take on a rainbow effect.
As luck would have it, when I read about this, I just happened to have 2 polarizers in my possession (Thanks, Jennifer!). For this shot, I actually used the light source as the subject itself. In between the 2 polarizers, I used a clear plastic lid from a CD case to achieve the rainbow colours. By underexposing a little, I was able to isolate the fluorescent bulb and make the colours appear to come from the light bulb and not the plastic CD lid just above it. I hope that makes sense. I'm a little confused myself. But it works!