This is old (2007). I used to work at the ad agency that had the Harley-Davidson account for a number of years. I always carry around a Moleskine sketchbook and take meeting notes on one side while doodling on the page next to it. This doodle ended up being used extensively in the Harley-Davidson "Dark Custom" campaign as well as on a line of Dark Custom Motorclothes.
It say's "FUCK YEAH" in it and they never noticed. :)
My sketchbook spread. This is actually a moleskin watercolor album which I'm mostly using to draw from life. This is sharp and spiky versus soft and fluffy. The models were the two of my house plants, and aim was a texture and light study.