Whistling while you work is for jerks.
If you have ever had a job where you worked with a whistler you know what I'm talking about. Its bad enough being over worked and under paid but when you have to endure countless hours of "Me and Julio down by the schoolyard" being whistled by someone who doesn't even realize they're whistling it's pure hell. I spent four years working with a whistler. It almost wrecked my life.