It's normal to have a small cloud of smoke, especially if it's been sitting awhile. A huge cloud (say one that would cover the entire back of the car) is not normal. Also, it is not normal to have smoke coming out of the exhaust after the engine is warm. That's a sign that something's wrong. I've never had a case where the Boxster "used" oil unless something was wrong.
I think MNBoxster (I believe that's who it was) explained it best when he said in the flat 6 engine, oil is trapped in the cylinder so at startup it blows a little smoke. Key word being "little".
