If you are the owner of wild keys which are trying to escape all the time, you may need this: a belt clip made of stainless steel. This should help to domesticate the beastly keys and to hold them on your side. 

Note: Now it is even more useful since I've added a bottle opener to it. As a german and particulary bavarian, I have to open a lot of beers! 

The belt clip comes without keychain or beer!