icon overlay stuck on desktop

While browsing in Safari, I rolled the mouse over a picture, and a pop-up name of the picture appeared. I left the screen and quit Safari, but the pop-up is now permanently displayed on my desktop. I can't drag it to the trash or delete it. It's a real pain because it overlays every file I open, and it blocks out the portion of the file beneath it. I've changed my desktop wallpaper but that did not help. It seems to be residing on top of every display. Can I post an image of it here?
It's a gray oblong background with the words, "Connecticut Expo Center - Home". I've returned to that site to see if I could un-resolve something that was left open but since I had left that screen and quit Safari, it must have been too late. Please help-this is a nuisance. Thanks

G4 eMac Mac OS X (10.3.9)