Inspired by this article on pvmgarage.com I recently created a generator for 3D CSS ribbons and made it available on css3d.net. It creates CSS and HTML code for a cross-browser compatible ribbon effect (not limited to CSS 3!) based on parameters for sizes and colors. The red headers you see in this screenshot are also generated like that:
Have fun with it and feel free to comment if you have any suggestions.
If you are interested in how it works, visit the aforementioned link or read about the CSS Triangle trick at css-tricks.com.