Keychains, wtf?

I've been thinking about keychains lately... no, not really. But, I really never understood the point of them, unless they could be of some use. I suppose it depends on your trade. Here are three I actually like.

“The Bullet” bicycle valve adapter.


http://www.chariandconyc.net/blog/new-arrival-the-bullet

Also, an earplug keychain I got at some CMW years ago.



Other than that, are there any other useful keyhains? Maybe an adapter for your phone?..


I am now officially procrastinating.