The following two articles list 25 cool code snippets for use on your site.
Included are:

Easy rounded corners
Ajax based contact forms
CSS shadows
Collapsing tables

…and lots of other goodies. See for yourself if it contains something useful:
Part IPart II

You’ve heard the buzz about the seperation of style from content, but you are stuck in the world of nested tables and deprecated markup. If so, you have come to the right place! Using CSS to style your (X)HTML files, will benefit you and your visitors in many ways.
A nice and free CSS tutorial can […]