There are two types of NiteIze clips.
One is the 'HipClip.'
http://www.niteize.com/product/HipClip.asp
Its okay, but will slide out of what ever compartment or pocket you keep the tool or knife in. I have several HipClips, but use them exclusively on tool/knives, that are in closed/zippered compartments in rucks or the like (have one clip on a Leatherman Juice in a pocket in my MaxPedition Monsoon Gearslinger).
For me, the HipClip dont work on a knife or tool, which resides in a jeans pocket. The knife/tool will slide up (and in a worst case scenario up and out of the pocket) when you sit down or remove the pants. Just doesnt work.
Luckily, NiteIze makes a far far better clip - the NiteIze 'Eclipse' which has teeth, that literally bite into jeans material. Annoying at first, but once you get the hang of it, the Eclipse is fantastic to use. You quickly learn to remove the knife (in my case) with the clip on from the pocket in one fluid motion. It will literally NEVER leave the top of the pocket no matter how many summersaults you make. A great and useful item.
I wont link to it, as I couldnt find it on the NiteIze site, but look for the words 'NiteIze Eclipse' on a well known auction site and it quickly pops up.
I heartily recommend the Eclipse (at least it works for me).
The CF modded Vic below is and will be my EDC SAK for the foreseeable future:
