I work in a "normal" office surrounded by lots of PCs and lights and overhead aircon ductings. We experimented with 3 new 3GS today, the compass'es pointed at three different directions in one instance. And when we place the 3 iphones side by side, sometimes they are in synch and sometimes they are not. So my question is: how much do you trust the compass? Is this only an inside-building behaviour? Outside the building the orientation seems ok.