Yesterday we blogged about radio-in-your-gnome-panel-applet RadioTray. It has an OK-ish default tray icon but it isn’t mono and that so distressed the awesome Tommy Brunn (of Caffeine fame) that, using his super design powers, he fashioned some replacement mono-icons for Radio Tray.
Get them @ http://gnome-look.org/content/show.php/Radiotray+mono+dark+icons?content=126396
The screenshot above also shows a mono-icon for Wakoopa which you can get here.