At home, it's almost always laying down. If it's not, the cats or the dog will make sure it is.
At the office, it's usually standing up. I have a coffee mug full of character ink pens, and I keep it in there with them.
In the car, it's usually right in between the 2, about a 45* angle. I stuff it in the leather cover around the shifter, easy to keep to and keeps it from falling anywhere.