Personally, I am a huge fan of negative space in design. This got me thinking while I was trying to accomplish something different. Normally a textual caption would be positioned above a background, but I wanted to do it the other way around: place the background in the letters.
I also wanted to add some nice dynamic effects to enhance the effect. This was amazingly easy to accomplish in jQuery with the use of a little creativity.
This article will explain what you need to do create an effect like this yourself.