Here is another vote for the Fenix L1P. I carry it in it's case in my back pocket next to my wallet and space pen. Don't even notice it there. I also have a Photon Freedom on my key chain. Unlike others, I do like this light for it's batteries. I can carry two in a little paper pouch in my wallet, so I always have a backups if needed. Since you do not need a screw driver to change the batteries they are easily replaceable.

I can't say enough about the Fenix lights and they are so reasonably priced too.

Ready