The trick is to use the background attribute with the different link states—with each state having a different version of the graphic. Repeat the graphic only once and then set the padding for the link so that the text is offset enough so that it does not cover the graphic bullet.
The yellow light bulb graphic is actually a background image behind the link text.
When the mouse pointer rolls over the link, the light bulb seems to glow. Actually, a new background image has replaced the initial image.