I snicker now and then when I read magazine articles recommending a tire pressure with no regard to terrain and rider weight. I don't know what the weight for a mountain biker is, but at 195-200#...I know that the recommended pressures that I read are not enough. I was perusing an article about the Kenda Nevegal one day and the reviewer wrote that the "best pressure for this tire" was in the neighborhood of 32psi. How can that apply to everyone? A 270# rider would be sitting on rim!
So...what's your tire size / psi / rider weight / terrain?
I'm usually ballin 2.3-2.4" 26'ers at 38psi. As I said, I weigh around 195 in the summer. I ride Kansas singletrack with quite a few rocks and roots as well as some smooth terrain.
When I go downtown, I bump the pressure up to at least 42psi b/c the square edges of stairs like to eat rims.