Doing a search for keychains I came across this interesting thread
on another site:

http://volokh.com/posts/1236654645.shtml

I think other EDCers will find it good reading. Check out especially
the use of antlers (!) as a defensive tool.

…But I still haven’t found a link to the best detachable multi key chain.

Somehow I don’t think the antlers will fit in my pocket.

;D