Anne van Kesteren provides a great CSS positioning resource on his (yes, his) site, simply titled Fixed positioning. If you are a Web designer/developer working with, or learning CSS, I highly recommend you look at his examples, as they may open your eyes to some layout possibilities that you may not be aware of.
I have a layout I’ve been working on, and I want to do it wholly with CSS, and I know it can be done in CSS, but I just don’t know enough to get it to work. :( I’ve been through dozens of sites and examples, and I still can’t get it.
If you’d like, I would be happy to take a look at it and perhaps help you figure out a way to lay it out with CSS. :)