* Create a square image depicting a circle, using as a side double the radius of the desired round corners' width(You can do that with any image editor, i.e. mspaint). We 'll use 16px radius for our corners in our example, thus we'll be needing a square image 32x32 pixels depicting a circle(with a radius of 16px obviously), with the same border/backround color combination, as the divs we'll inclose.

i.e. -> http://img137.imageshack.us/img137/3000/circleq.png

CSS Code: