2005 was the year of AJAX frameworks. 2008 seems to be the year of CSS frameworks. I think CSS frameworks are a good idea. Why???? Well they provide a great starting point and are easily tweaked. I am currently using Formy (form layout) and Hartija (print friendly stylesheets) in a project.
I can’t seem to master enough CSS techniques!!!! If you ever think you’ll need to implement a block hover effect, tabs, A-Z indexes, pagination, quotes, sitemaps and more - check out 101 CSS Techniques of all Time Part 2. Theres also a Part 1.