I have a blackrapid... I think. It's one of those ones that slings over your shoulder and allows you to drop the camera without worrying much. I love this thing for anytime I'm using the camera on a professional gig. Gives me a lot of freedom and allows me to rest the camera more easily.
I also have a detachable one... crap... can't remember... ugh... *goes to look* Ok, it's a tamrac and it has plastic clips that decouple easily. Allows me to switch quickly between standard shoulder strap and the blackrapid. My only complaint with the strap is that the clips are plastic and that makes me a tiny bit nervous. I've been using two of them for about two years now, and I'm pretty confident in them.