As is common with techniques that use Web standards, when implemented, they don’t work with Internet Explorer (IE). This is one simple technique that uses very simple CSS that adjusts the border radius, but alas, croaks in IE.
Failing to be impressed with a lack of images, one can opt for images with this technique. The CSS gets a little shorter and slightly more elegant — now we’re getting somewhere reasonable.
But if you like to live on the edge and you crave more code that you can shake a stick at, then Curvy Corners is for you. It’s all JS, all the time. It will create on-the-fly rounded corners for any HTML DIV element, that (supposedly) looks as good as any graphically created corners.
If none of the above solutions peak your interest, then feel free to peruse the full list of rounded corner solutions.