circular button

How do I create a circular button? Because it seems like all buttons are rectangular, right? JButton and Button are both rectangles. I know I can use a GIF as the image of the Button, but I want the button itself to be a circle. Also, if that is impossible for the button to be a circle, how do I make the button a square but the image a circle with everyting surrounding the circule in the button the same color as the background. That is, how do I make it invisible except for the circle?

[497 byte] By [mhbfca] at [2007-10-2 16:50:03]