I'm assuming it was looked at and not a viable option (either due to cost, h/w constraints, time to market etc.). It's possible Nokia didn't consider it. Either way, we don't have it - and it does suck. I'd love to have (or develop) an AR app. I think it's a fun toy and will have interesting and compelling mainstream use cases too. However, for me, the advantages of the N900 over another device outweigh the disadvantage of no magnetometer. And there's nothing I can do to make the N900 have one (unless we can tack one on via USB)