Sci Am has two articles out in their Scientific American Mind magazine that deal with creativity. The first discusses the connection between creativity and eccentricity:
The second is a slideshow of ways to cultivate your creativity. The slideshow discusses general exercises one can follow to encourage creative thinking. It seems fine but a little more abstract than I prefer. The slideshow is a little annoying in that for me, the image was low enough that i had to scroll down to see it all, for each and every slide.