What's an Australian slang synonym for a wild rumor or improbable story? Furphy!
Wikipedia explains that the word "furphy"may have come into use because water carts made by J. Furphy & Sons of Victoria were used to take water to Australian Army personnel in World War I; they became gathering places for the soldiers to exchange gossip and news.
Wikipedia notes that "scuttlebutt" came about similarly, as a scuttlebutt was a water cask on a ship, where the sailors gathered around to exchange stories.
Now we just have office coolers, which haven't made their way into such metonymous use. Yet.