As part of creating my new blog, I mentioned that I threw some CSS onto my website. I'd been a bit reluctant to do this before, because there's usually a lot of boilerplate CSS to write before you can do anything interesting.
Last February, Yahoo! released a set of web development libraries under a BSD licence; among these were some CSS components. They are relatively painless to drop in, and simplify making fonts consistent across browsers, for example. The 'Grids' component makes creating columnar layouts without tables fairly straightforward.