essentially does the same thing as my other style sheet [here: http://freestyler.ws/style/1627/link-icons-specifically-tailored-for-mac-users],
except in this style, the icons only appear when mousing over links and they disappear when moving the mouse away from links.

p.s. if you are using the GreaseKit add-on for Safari, you may load this as a user script. if wrapped in script, most css styles (including this one) are fully compatible with GreaseKit.