I remember most pictures of iPhones being bent backwards, the screen outwards. Is that correct? I can't recall any photos of the phone bending towards the screen. If so, maybe that would indicate it's better to put the phone glass side in.
Glass inward for me, with the phone upside-down (home button on top). I don't do it to protect the screen, but more because the orientation makes more sense when putting the phone in your pocket.