Just one. My original, still working after 5 years, knock on wood. Usually doesn't have SIM since N9 fits pants pocket better. The downside to a diet that worked, perhaps. It did get pressed back into service while I was N9-less after my unicorn died of frostbite.

It's often found in the living room where the combination of Copernicus' Pierogi with XBMC remote makes it quite useful.

And also: that.little hole is for a strap? Wow! Who knew? Not me, for one. Still learning new stuff about the ol' N900.