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.
CSS frameworks are a great idea - I wonder whether there are superior implementations? While 'Grids' is nice, there seems to be certain limits on how complex a layout you can really create with it - although you can get a long way, and it's worth trying out. I've not looked at the rest of the YUI, but perhaps all those Javascript components are useful as well.