I´ve been looking in to CSS3 more and more lately and I can just say that i´m amazed by the great stuff in there, especially the rounded borders rule. Since the new releases of Opera, Safari and FireFox it´s now possible to use a lot of the great CSS3 rules in your projects. This does not only save you time. It also keeps the requests to your servers down (no calling for images sprites, well not as many anyway). But, how about IE6, IE7 and IE8? We all know of the big problems with the IE-browsers. It just make us nuts. But now, thanks to a great guy over att htmlremix.com (Great job Remiz!) you can now use a wounderfull *.htc file to get these crazy browsers to behave correctly and display rounded corners with the great CSS3 rule, -moz-border-radius. But since its not standard yet, your css-files will not validate. But hey, have they ever? It´s all about making conditional styles for IE anyway. Until CSS3 get standard and it will be, you´ll be safe with this file. However, there is also other ways around it. Jquery uses an great library for the CSS3 selectors and gives all browser the correct styles to. But why use Jquery when you can use pure css and an little tiny smart *.htc file.
Just look at this smart code snipplet.
.curved {
-moz-border-radius:10px;
behavior:url(border-radius.htc);
}
And voila, you are safe.