Okay, i think misha is talking about the actual plastic clip that the caribiner is clipped onto... Just to clear that up. Additionally, there was another messenger bag thread a while back where I explained that the reason I came up with the carabiner idea was so that I COULD wear my bag low, because, well, that's where I like it. I carry 2 composition books, bike lock, tools/spare/pump, one notebook, and occasionally a text book. Since I'm not carrying a ton of stuff I just prefer to have it low, it's more comfortable for me. And I don't wear the cross strap, it would probably be redundant to wear the cross strap and carabiner, I use the carabiner as an alternative cause it is easier and I don't need it to be load-bearing, it is just there to keep the bag from sliding around to the front when I ride. If i'm getting groceries I ride my pos 198x motobecane with the big home-made wooden box on the back.
Misha, if you are going to be using the clip/ carabiner like I do just to keep the bag stable, then you could always sew a loop onto the side of the bag to clip the carabiner to.
Didn't know bags could cause such a stir, i just experimented until I found out what worked for me!