Twenty tar balls have been found off Key West, though the Coast Guard stopped short of saying whether they came from the massive Gulf oil spill. The balls, which were 3-to-8 inches in diameter, were discovered yesterday by the Florida Park Service and have been sent to a lab for analysis. Tar balls have been washing ashore in several states along the coast; scientists are worried that oil is getting caught in a major ocean current that could carry it through the Florida Keys and up the East Coast. (More tar balls stories.)