I shave about once every two or three weeks.
But I never shave it COMPLETELY off. I leave just enough that if you were to stand next to me you could still see it. I like that look.
My roommate on the other hand, shaves every two days. The way he acts when he doesn't shave, you'd think facial hair is akin to the devil for him. Although the one time he went almost a week without shaving I honestly couldn't tell he had. That guy doesn't grow facial hair worth a damn.