In the following entry, it is assumed you want rounded corners. For the record, I, FJ, like rounded and square corners about just as much and have no particular bias towards any. I do believe however a well-designed page can mix both and, in many cases, should mix both so as to provide proper visual information to its readers.
Yet, the more I read about the “proper” ways to implement them with CSS, the more I wonder. We all know the “proper” way is CSS3 and that it will have to wait — a long time. CSS2 provides us at best with vendor-specific extensions or unsupported declarations. Meanwhile, we all strive to deliver round corners that are vaguely compatible with Internet Explorer (because not everyone uses Safari) and don’t litter the code.
After all, I’m only FJ so I’m sure I’m missing something big. I know many of you are experts on web design matters. Would you care to enlighten me?