This could be the most amazing thing you see all day....
Two colleagues of mine attended a wedding in Idaho last month and, while driving back to Portland, discovered the Snake River frozen over. Like all good-hearted Americans, they decided to pull over and toss rocks at it. The unworldly, echoing sound-effects that ensued are stunning, worthy of both National Geographic and Star Trek.
A quick head's up though. The gent in the "O" hat has quite the potty-mouth on him and breaks out a few Big Lebowski quotes. NSFW? I'll let you decide.